Internet

The Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic and optical networking technologies. The Internet carries a vast range ofinformation resources and services, such as the inter-linked hypertext documents of the World Wide Web (WWW) and the infrastructure to support electronic mail.

Most traditional communications media including telephone, music, film, and television are being reshaped or redefined by the Internet. Newspaper, book and other print publishing are having to adapt to Web sites and blogging (Dell XPS M1210 Battery) http://www.hdd-shop.co.uk .

The Internet has enabled or accelerated new forms of human interactions through instant messaging, Internet forums, and social networking. Online shopping has boomed both for major retail outlets and small artisans and traders. Business-to-business and financial services on the Internet affect supply chains across entire industries (Dell Studio XPS 1340 Battery) .

The origins of the Internet reach back to the 1960s with both private and United States military research into robust, fault-tolerant, and distributed computer networks. The funding of a new U.S. backbone by the National Science Foundation, as well as private funding for other commercial backbones, led to worldwide participation in the development of new networking technologies, and the merger of many networks (Dell Studio XPS 1640 Battery) .

The commercialization of what was by then an international network in the mid 1990s resulted in its popularization and incorporation into virtually every aspect of modern human life. As of 2009, an estimated quarter of Earth's population used the services of the Internet (Dell Vostro 1710 Battery) .

The Internet has no centralized governance in either technological implementation or policies for access and usage; each constituent network sets its own standards. Only the overreaching definitions of the two principal name spaces in the Internet, the Internet Protocol address space and the Domain Name System, are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers (ICANN) (Sony VGP-BPS13 battery) .

The technical underpinning and standardization of the core protocols (IPv4 and IPv6) is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise (Sony VGP-BPS13/B battery) .

Terminology

Internet is a short form of the technical term "internetwork", the result of interconnecting computer networks with special gateways (routers). The Internet is also often referred to as the Net (Sony VGP-BPS13/S battery) .

The term the Internet, when referring to the entire global system of IP networks, has traditionally been treated as a proper noun and written with an initial capital letter. In the media and popular culture a trend has developed to regard it as a generic term or common noun and thus write it as "the internet", without capitalization (Sony VGP-BPS13A/B battery) .

The terms Internet and World Wide Web are often used in everyday speech without much distinction. However, the Internet and the World Wide Web are not one and the same. The Internet is a global data communications system. It is a hardware and software infrastructure that provides connectivity between computers (Sony VGP-BPS13B/B battery) .

In contrast, the Web is one of the services communicated via the Internet. It is a collection of interconnected documents and other resources, linked by hyperlinks and URLs.

In many technical illustrations when the precise location or interrelation of Internet resources is not important, extended networks such as the Internet are often depicted as a cloud (Sony VGP-BPL9 battery) .

The verbal image has been formalized in the newer concept of cloud computing.

History

The USSR's launch of Sputnik spurred the United States to create the Advanced Research Projects Agency (ARPA or DARPA) in February 1958 to regain a technological lead (Sony VGP-BPS13B/B battery) .

ARPA created theInformation Processing Technology Office (IPTO) to further the research of the Semi Automatic Ground Environment (SAGE) program, which had networked country-wide radar systems together for the first time (Sony VGP-BPS13B/B battery) .

The IPTO's purpose was to find ways to address the US Military's concern about survivability of their communications networks, and as a first step interconnect their computers at thePentagon, Cheyenne Mountain, and Strategic Air Command headquarters (SAC). J. C. R. Licklider, a promoter of universal networking, was selected to head the IPTO (Sony VGP-BPL11 battery) .

Licklider moved from the Psycho-Acoustic Laboratory at Harvard University to MIT in 1950, after becoming interested in information technology. At MIT, he served on a committee that established Lincoln Laboratory and worked on the SAGE project. In 1957 he became a Vice President at BBN, where he bought the first production PDP-1 computer and conducted the first public demonstration of time-sharing (Sony VGP-BPL15 battery) .

Professor Leonard Kleinrockwith one of the first ARPANETInterface Message Processors at UCLA

At the IPTO, Licklider's successor Ivan Sutherland in 1965 got Lawrence Roberts to start a project to make a network, and Roberts based the technology on the work of Paul Baran (Dell Inspiron E1505 battery) ,

who had written an exhaustive study for the United States Air Force that recommended packet switching (opposed to circuit switching) to achieve better network robustness and disaster survivability. Roberts had worked at the MIT Lincoln Laboratory originally established to work on the design of the SAGE system (Dell Latitude E6400 battery) .

UCLA professor Leonard Kleinrock had provided the theoretical foundations for packet networks in 1962, and later, in the 1970s, for hierarchical routing, concepts which have been the underpinning of the development towards today's Internet (HP Pavilion dv6000 Battery) .

Sutherland's successor Robert Taylor convinced Roberts to build on his early packet switching successes and come and be the IPTO Chief Scientist. Once there, Roberts prepared a report called Resource Sharing Computer Networks which was approved by Taylor in June 1968 and laid the foundation for the launch of the working ARPANET the following year (Sony Vaio VGN-FZ31S battery) .

After much work, the first two nodes of what would become the ARPANET were interconnected between Kleinrock's Network Measurement Center at the UCLA's School of Engineering and Applied Science and Douglas Engelbart's NLS system at SRI International (SRI) in Menlo Park, California, on 29 October 1969 (Sony VGN-FZ31S battery) .

The third site on the ARPANET was the Culler-Fried Interactive Mathematics center at the University of California at Santa Barbara, and the fourth was the University of UtahGraphics Department. In an early sign of future growth, there were already fifteen sites connected to the young ARPANET by the end of 1971 (SONY VGN-FZ38M Battery) .

The ARPANET was one of the eve networks of today's Internet. In an independent development, Donald Davies at the UK National Physical Laboratory also discovered the concept of packet switching in the early 1960s, first giving a talk on the subject in 1965, after which the teams in the new field from two sides of the Atlantic ocean first became acquainted (SONY VGN-FZ31z Battery) .

It was actually Davies' coinage of the wording "packet" and "packet switching" that was adopted as the standard terminology. Davies also built a packet switched network in the UK called the Mark I in 1970. Bolt Beranek and Newman (BBN), the private contractors for ARPANET, set out to create a separate commercial version after establishing "value added carriers" was legalized in the U.S (Sony VGN-FZ31Z Battery) .

The network they established was called Telenet and began operation in 1975, installing free public dial-up access in cities throughout the U.S. Telenet was the first packet-switching network open to the general public.

Following the demonstration that packet switching worked on the ARPANET (SONY VAIO VGN-FZ38M Battery) ,

the British Post Office, Telenet, DATAPAC and TRANSPAC collaborated to create the first international packet-switched network service. In the UK, this was referred to as the International Packet Switched Service (IPSS), in 1978. The collection of X.25-based networks grew from Europe and the US to cover Canada, Hong Kong and Australia by 1981 (SONY VGN-FZ31E Battery) .

The X.25 packet switching standard was developed in the CCITT (now called ITU-T) around 1976.

The early ARPANET ran on the Network Control Program (NCP), implementing the host-to-host connectivity and switching layers of the protocol stack, designed and first implemented in December 1970 by a team called the Network Working Group (NWG) led by Steve Crocker (SONY VGN-FZ31J Battery) .

To respond to the network's rapid growth as more and more locations connected, Vinton Cerf and Robert Kahn developed the first description of the now widely used TCP protocols during 1973 and published a paper on the subject in May 1974 (SONY VGN-FZ31M Battery) .

Use of the term "Internet" to describe a single global TCP/IP network originated in December 1974 with the publication of RFC 675, the first full specification of TCP that was written by Vinton Cerf, Yogen Dalal and Carl Sunshine, then at Stanford University. During the next nine years, work proceeded to refine the protocols and to implement them on a wide range of operating systems (SONY VGN-FZ31B Battery) .

The first TCP/IP-based wide-area network was operational by 1 January 1983 when all hosts on the ARPANET were switched over from the older NCP protocols. In 1985, the United States' National Science Foundation (NSF) commissioned the construction of the NSFNET, a university 56 kilobit/second network backbone using computers called "fuzzballs" by their inventor, David L. Mills (SONY VGP-BPS13 Battery) .

The following year, NSF sponsored the conversion to a higher-speed 1.5 megabit/second network. A key decision to use the DARPA TCP/IP protocols was made by Dennis Jennings, then in charge of the Supercomputer program at NSF.

The opening of the NSFNET to other networks began in 1988 (Dell Inspiron 1320 Battery) .

The US Federal Networking Council approved the interconnection of the NSFNET to the commercialMCI Mail system in that year and the link was made in the summer of 1989. Other commercial electronic mail services were soon connected, including OnTyme, Telemail and Compuserve (Dell Inspiron 1320n Battery) .

In that same year, three commercial Internet service providers (ISPs) began operations: UUNET, PSINet, and CERFNET. Important, separate networks that offered gateways into, then later merged with, the Internet include Usenet and BITNET. Various other commercial and educational networks (Dell Inspiron 1464 Battery) ,

such as Telenet (by that time renamed to Sprintnet), Tymnet, Compuserve and JANET were interconnected with the growing Internet in the 1980s as the TCP/IP protocol became increasingly popular. The adaptability of TCP/IP to existing communication networks allowed for rapid growth (Dell Inspiron 1564 Battery) .

The open availability of the specifications and reference code permitted commercial vendors to build interoperable network components, such as routers, making standardized network gear available from many companies. This aided in the rapid growth of the Internet and the proliferation of local-area networking (Dell Inspiron 1764 Battery) .

It seeded the widespread implementation and rigorous standardization of TCP/IP on UNIX and virtually every other common operating system.

Although the basic applications and guidelines that make the Internet possible had existed for almost two decades, the network did not gain a public face until the 1990s (Dell Studio 1450 Battery) .

On 6 August 1991, CERN, a pan European organization for particle research, publicized the new World Wide Web project. The Web was invented by British scientist Tim Berners-Lee in 1989. An early popular web browser was ViolaWWW, patterned after HyperCard and built using the X Window System (Dell Studio 1457 Battery) .

It was eventually replaced in popularity by the Mosaic web browser. In 1993, the National Center for Supercomputing Applications at the University of Illinois released version 1.0 of Mosaic, and by late 1994 there was growing public interest in the previously academic, technical Internet (Dell Latitude D610 Battery) .

By 1996 usage of the word Internet had become commonplace, and consequently, so had its use as a synecdoche in reference to the World Wide Web.

Meanwhile, over the course of the decade, the Internet successfully accommodated the majority of previously existing public computer networks (although some networks, such as FidoNet, have remained separate) (Toshiba NB100 Battery) .

During the late 1990s, it was estimated that traffic on the public Internet grew by 100 percent per year, while the mean annual growth in the number of Internet users was thought to be between 20% and 50%. This growth is often attributed to the lack of central administration (Toshiba Satellite M65 battery) ,

which allows organic growth of the network, as well as the non-proprietary open nature of the Internet protocols, which encourages vendor interoperability and prevents any one company from exerting too much control over the network. The estimated population of Internet users is 1.97 billion as of 30 June 2010 (Toshiba Satellite M60 battery) .

From 2009 onward, the Internet is expected to grow significantly in Brazil, Russia, India, China, and Indonesia (BRICI countries). These countries have largepopulations and moderate to high economic growth, but still low Internet penetration rates (Dell Latitude D830 Battery) .

In 2009, the BRICI countries represented about 45 percent of the world's population and had approximately 610 million Internet users, but by 2015, Internet users in BRICI countries will double to 1.2 billion, and will triple in Indonesia (Dell Latitude D620 Battery) .

Technology

Protocols

The complex communications infrastructure of the Internet consists of its hardware components and a system of software layers that control various aspects of the architecture (Dell Inspiron Mini 10 Battery) .

While the hardware can often be used to support other software systems, it is the design and the rigorous standardization process of the software architecture that characterizes the Internet and provides the foundation for its scalability and success. The responsibility for the architectural design of the Internet software systems has been delegated to the Internet Engineering Task Force (IETF) (Sony VGN-FW11S Battery) .

The IETF conducts standard-setting work groups, open to any individual, about the various aspects of Internet architecture. Resulting discussions and final standards are published in a series of publications, each called aRequest for Comments (RFC), freely available on the IETF web site (Sony VGN-FW11M Battery) .

The principal methods of networking that enable the Internet are contained in specially designated RFCs that constitute the Internet Standards. Other less rigorous documents are simply informative, experimental, or historical, or document the best current practices (BCP) when implementing Internet technologies (Sony VGN-FW139E/H battery) .

The Internet Standards describe a framework known as the Internet Protocol Suite. This is a model architecture that divides methods into a layered system of protocols (RFC 1122, RFC 1123). The layers correspond to the environment or scope in which their services operate (Dell Latitude E5400 Battery) .

At the top is the Application Layer, the space for the application-specific networking methods used in software applications, e.g., a web browser program. Below this top layer, the Transport Layer connects applications on different hosts via the network (e.g., client–server model) with appropriate data exchange methods (Dell Latitude E4200 Battery) .

Underlying these layers are the core networking technologies, consisting of two layers. The Internet Layer enables computers to identify and locate each other via Internet Protocol (IP) addresses, and allows them to connect to one-another via intermediate (transit) networks (Dell Vostro A840 Battery) .

Lastly, at the bottom of the architecture, is a software layer, the Link Layer, that provides connectivity between hosts on the same local network link, such as a local area network (LAN) or a dial-up connection. The model, also known as TCP/IP, is designed to be independent of the underlying hardware which the model therefore does not concern itself with in any detail (Dell Inspiron 300M Battery) .

Other models have been developed, such as the Open Systems Interconnection (OSI) model, but they are not compatible in the details of description, nor implementation, but many similarities exist and the TCP/IP protocols are usually included in the discussion of OSI networking (Dell Studio 1737 battery) .

The most prominent component of the Internet model is the Internet Protocol (IP) which provides addressing systems (IP addresses) for computers on the Internet. IP enables internetworking and essentially establishes the Internet itself. IP Version 4 (IPv4) is the initial version used on the first generation of the today's Internet and is still in dominant use (Dell Inspiron E1505 battery) .

It was designed to address up to ~4.3 billion (109) Internet hosts. However, the explosive growth of the Internet has led to IPv4 address exhaustion which is estimated to enter its final stage in approximately 2011. A new protocol version, IPv6, was developed in the mid 1990s which provides vastly larger addressing capabilities and more efficient routing of Internet traffic (Dell RM791 battery) .

IPv6 is currently in commercial deployment phase around the world and Internet address registries (RIRs) have begun to urge all resource managers to plan rapid adoption and conversion.

IPv6 is not interoperable with IPv4 (Dell XPS M1530 battery) .

It essentially establishes a "parallel" version of the Internet not directly accessible with IPv4 software. This means software upgrades or translator facilities are necessary for every networking device that needs to communicate on the IPv6 Internet. Most modern computer operating systems are already converted to operate with both versions of the Internet Protocol (Dell XPS M2010 battery) .

Network infrastructures, however, are still lagging in this development. Aside from the complex physical connections that make up its infrastructure, the Internet is facilitated by bi- or multi-lateral commercial contracts (e.g., peering agreements), and by technical specifications or protocols that describe how to exchange data over the network (Dell Vostro 1000 battery) .

Indeed, the Internet is defined by its interconnections and routing policies.

Structure

The Internet structure and its usage characteristics have been studied extensively. It has been determined that both the Internet IP routing structure and hypertext links of the World Wide Web are examples of scale-free networks (Acer Aspire One battery) .

Similar to the way the commercial Internet providers connect via Internet exchange points, research networks tend to interconnect into large subnetworks such asGEANT, GLORIAD, Internet2 (successor of the Abilene Network), and the UK's national research and education network JANET (Toshiba Satellite P10 Battery) .

These in turn are built around smaller networks (see also the list ofacademic computer network organizations).

Many computer scientists describe the Internet as a "prime example of a large-scale, highly engineered, yet highly complex system" (SONY VGN-FZ210CE Battery) .

The Internet is extremely heterogeneous; for instance, data transfer rates and physical characteristics of connections vary widely. The Internet exhibits "emergent phenomena" that depend on its large-scale organization. For example, data transfer rates exhibit temporal self-similarity (Dell Precision M70 Battery) .

The principles of the routing and addressing methods for traffic in the Internet reach back to their origins the 1960s when the eventual scale and popularity of the network could not be anticipated. Thus, the possibility of developing alternative structures is investigated (Toshiba Satellite L305 Battery) .

Governance

The Internet is a globally distributed network comprising many voluntarily interconnected autonomous networks. It operates without a central governing body (Toshiba Satellite T4900 Battery) .

However, to maintain interoperability, all technical and policy aspects of the underlying core infrastructure and the principal name spaces are administered by the Internet Corporation for Assigned Names and Numbers (ICANN), headquartered in Marina del Rey, California (Toshiba PA3399U-2BRS battery) .

ICANN is the authority that coordinates the assignment of unique identifiers for use on the Internet, including domain names, Internet Protocol (IP) addresses, application port numbers in the transport protocols, and many other parameters. Globally unified name spaces, in which names and numbers are uniquely assigned, are essential for the global reach of the Internet (Toshiba Satellite A200 Battery) .

ICANN is governed by an international board of directors drawn from across the Internet technical, business, academic, and other non-commercial communities. The US government continues to have the primary role in approving changes to the DNS root zone that lies at the heart of the domain name system (Toshiba Satellite 1200 Battery) .

ICANN's role in coordinating the assignment of unique identifiers distinguishes it as perhaps the only central coordinating body on the global Internet. On 16 November 2005, the World Summit on the Information Society, held in Tunis, established the Internet Governance Forum (IGF) to discuss Internet-related issues (Toshiba Satellite M300 Battery) .

Modern uses

The Internet is allowing greater flexibility in working hours and location, especially with the spread of unmetered high-speed connections and web applications WD passport essential (500GB/640GB) .

The Internet can now be accessed almost anywhere by numerous means, especially through mobile Internet devices. Mobile phones, datacards, handheld game consoles and cellular routers allow users to connect to the Internet from anywhere there is a wireless network supporting that device's technology WD passport essential (250GB/320GB) .

Within the limitations imposed by small screens and other limited facilities of such pocket-sized devices, services of the Internet, including email and the web, may be available. Service providers may restrict the services offered and wireless data transmission charges may be significantly higher than other access methods WD passport essential SE (750GB/1TB) .

Educational material at all levels from pre-school to post-doctoral is available from websites. Examples range from CBeebies, through school and high-school revision guides, virtual universities, to access to top-end scholarly literature through the likes of Google Scholar WD passport elite(250GB/320GB) .

In distance education, help with homework and other assignments, self-guided learning, whiling away spare time, or just looking up more detail on an interesting fact, it has never been easier for people to access educational information at any level from anywhere. The Internet in general and the World Wide Web in particular are important enablers of both formal and informal education WD passport elite(500GB/640GB) .

The low cost and nearly instantaneous sharing of ideas, knowledge, and skills has made collaborative work dramatically easier, with the help of collaborative software. Not only can a group cheaply communicate and share ideas, but the wide reach of the Internet allows such groups to easily form in the first place WD passport studio for Mac(320GB/500GB) .

An example of this is the free software movement, which has produced, among other programs, Linux, Mozilla Firefox, and OpenOffice.org. Internet "chat", whether in the form of IRC chat rooms or channels, or via instant messaging systems, allow colleagues to stay in touch in a very convenient way when working at their computers during the day WD passport studio for Mac(500GB/640GB) .

Messages can be exchanged even more quickly and conveniently than via e-mail. Extensions to these systems may allow files to be exchanged, "whiteboard" drawings to be shared or voice and video contact between team members WD Elements series(250GB/320GB) .

Version control systems allow collaborating teams to work on shared sets of documents without either accidentally overwriting each other's work or having members wait until they get "sent" documents to be able to make their contributions. Business and project teams can share calendars as well as documents and other information WD Elements SE(500GB/640GB) .

Such collaboration occurs in a wide variety of areas including scientific research, software development, conference planning, political activism and creative writing. Social and political collaboration is also becoming more widespread as both Internet access and computer literacy grow WD Elements SE(750GB/1TB) .

From the flash mob 'events' of the early 2000s to the use of social networking in the 2009 Iranian election protests, the Internet allows people to work together more effectively and in many more ways than was possible without it.

The Internet allows computer users to remotely access other computers and information stores easily, wherever they may be across the world WD Elements desktop(500GB/640GB) .

They may do this with or without the use of security, authentication and encryption technologies, depending on the requirements. This is encouraging new ways of working from home, collaboration and information sharing in many industries. Anaccountant sitting at home can audit the books of a company based in another country, on a server situated in a third country that is remotely maintained by IT specialists in a fourth WD Elements desktop(750GB/1TB) .

These accounts could have been created by home-working bookkeepers, in other remote locations, based on information e-mailed to them from offices all over the world. Some of these things were possible before the widespread use of the Internet, but the cost of private leased lines would have made many of them infeasible in practice WD Elements desktop(1.5 TB/2TB) .

An office worker away from their desk, perhaps on the other side of the world on a business trip or a holiday, can open a remote desktop session into his normal office PC using a secure Virtual Private Network (VPN) connection via the Internet. This gives the worker complete access to all of his or her normal files and data, including e-mail and other applications, while away from the officeWD passport essential SE (750GB/1TB)--USB 3.0) .

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Services

Information

Many people use the terms Internet and World Wide Web, or just the Web, interchangeably, but the two terms are not synonymous. The World Wide Web is a global set of documents, images and other resources, logically interrelated by hyperlinks and referenced with Uniform Resource Identifiers (URIs) WD passport for Mac(320GB/500GB) .

URIs allow providers to symbolically identify services and clients to locate and address web servers, file servers, and other databases that store documents and provide resources and access them using the Hypertext Transfer Protocol (HTTP), the primary carrier protocol of the Web WD passport for Mac(640GB/1TB) .

HTTP is only one of the hundreds of communication protocols used on the Internet. Web services may also use HTTP to allow software systems to communicate in order to share and exchange business logic and data My book essential 4 generation (640GB/1TB) .

World Wide Web browser software, such as Microsoft's Internet Explorer, Mozilla Firefox, Opera, Apple's Safari, and Google Chrome, let users navigate from one web page to another via hyperlinks embedded in the documents. These documents may also contain any combination of computer data WD My book essential 4 generation( 1.5TB/2TB) ,

including graphics, sounds, text, video, multimedia and interactive content including games, office applications and scientific demonstrations. Through keyword-driven Internet research using search engines like Yahoo! and Google, users worldwide have easy, instant access to a vast and diverse amount of online information WD My book elite( 1TB/1.5TB) .

Compared to printed encyclopedias and traditional libraries, the World Wide Web has enabled the decentralization of information.

The Web has also enabled individuals and organizations to publish ideas and information to a potentially large audience online at greatly reduced expense and time delay WD My book studio(1TB/2TB) .

Publishing a web page, a blog, or building a website involves little initial cost and many cost-free services are available. Publishing and maintaining large, professional web sites with attractive, diverse and up-to-date information is still a difficult and expensive proposition, however WD My book essential 4 generation( 1.5TB/2TB) .

Many individuals and some companies and groups use web logs or blogs, which are largely used as easily updatable online diaries. Some commercial organizations encourage staff to communicate advice in their areas of specialization in the hope that visitors will be impressed by the expert knowledge and free information, and be attracted to the corporation as a result WD My book elite(640GB/2TB) .

One example of this practice is Microsoft, whose product developers publish their personal blogs in order to pique the public's interest in their work. Collections of personal web pages published by large service providers remain popular, and have become increasingly sophisticated Seagate expansion portable (320GB/500GB) .

Whereas operations such as Angelfire and GeoCities have existed since the early days of the Web, newer offerings from, for example, Facebook and MySpace currently have large followings. These operations often brand themselves as social network services rather than simply as web page hosts Seagate expansion (1.5TB/2TB) .

Advertising on popular web pages can be lucrative, and e-commerce or the sale of products and services directly via the Web continues to grow.

When the Web began in the 1990s, a typical web page was stored in completed form on a web server, formatted with HTML, ready to be sent to a user's browser in response to a request Seagate Freeagent Desktop (500GB/1TB) .

Over time, the process of creating and serving web pages has become more automated and more dynamic. Websites are often created using content management or wiki software with, initially, very little content. Contributors to these systems, who may be paid staff, members of a club or other organization or members of the public Seagate Freeagent Go(250GB/320GB) ,

fill underlying databases with content using editing pages designed for that purpose, while casual visitors view and read this content in its final HTML form. There may or may not be editorial, approval and security systems built into the process of taking newly entered content and making it available to the target visitors Seagate Freeagent Go(500GB/640GB) .

Communication

E-mail is an important communications service available on the Internet. The concept of sending electronic text messages between parties in a way analogous to mailing letters or memos predates the creation of the Internet Seagate Freeagent Go(750GB/1TB) .

Today it can be important to distinguish between internet and internal e-mail systems. Internet e-mail may travel and be stored unencrypted on many other networks and machines out of both the sender's and the recipient's control. During this time it is quite possible for the content to be read and even tampered with by third parties Seagate Freeagent Goflex(250GB/320GB) ,

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Interoperability between different providers has improved and the ability to call or receive a call from a traditional telephone is available. Simple, inexpensive VoIP network adapters are available that eliminate the need for a personal computer.

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Data transfer

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A computer file can be e-mailed to customers, colleagues and friends as an attachment. It can be uploaded to a website or FTP server for easy download by others. It can be put into a "shared location" or onto a file server for instant use by colleagues. The load of bulk downloads to many users can be eased by the use of "mirror" servers or peer-to-peer networks Samsung S2 protable (320GB/500GB) .

In any of these cases, access to the file may be controlled by user authentication, the transit of the file over the Internet may be obscured byencryption, and money may change hands for access to the file. The price can be paid by the remote charging of funds from, for example, a credit card whose details are also passed—usually fully encrypted—across the Internet Samsung S1 Mini (120GB/160GB) .

The origin and authenticity of the file received may be checked by digital signatures or by MD5 or other message digests. These simple features of the Internet, over a worldwide basis, are changing the production, sale, and distribution of anything that can be reduced to a computer file for transmission Samsung S1 Mini (250GB/320GB) .

This includes all manner of print publications, software products, news, music, film, video, photography, graphics and the other arts. This in turn has caused seismic shifts in each of the existing industries that previously controlled the production and distribution of these products Samsung story station (1TB/1.5TB) .

Streaming media refers to the act that many existing radio and television broadcasters promote Internet "feeds" of their live audio and video streams (for example, the BBC). They may also allow time-shift viewing or listening such as Preview, Classic Clips and Listen Again features Samsung Story station (1.5TB/2TB) .

These providers have been joined by a range of pure Internet "broadcasters" who never had on-air licenses. This means that an Internet-connected device, such as a computer or something more specific, can be used to access on-line media in much the same way as was previously possible only with a television or radio receiver Samsung story station Esata(1TB/1.5TB) .

The range of available types of content is much wider, from specialized technical webcasts to on-demand popular multimedia services. Podcasting is a variation on this theme, where—usually audio—material is downloaded and played back on a computer or shifted to a portable media player to be listened to on the move Samsung G3 station (1TB/1.5TB) .

These techniques using simple equipment allow anybody, with little censorship or licensing control, to broadcast audio-visual material worldwide.

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As example for standard image quality needs 1 Mbps internet speed for SD 480p, requires 2.5 Mbps for HD 720p quality and the top-of-the-line HDX quality needs 4.5 Mbps for 1080p.

Webcams can be seen as an even lower-budget extension of this phenomenon Maxtor one touch 4 plus (1TB/1.5TB) .

While some webcams can give full-frame-rate video, the picture is usually either small or updates slowly. Internet users can watch animals around an African waterhole, ships in the Panama Canal, traffic at a local roundabout or monitor their own premises, live and in real time Maxtor cool black(640GB/1TB) .

Video chat rooms and video conferencingare also popular with many uses being found for personal webcams, with and without two-way sound. YouTube was founded on 15 February 2005 and is now the leading website for free streaming video with a vast number of users Maxtor Black diamond (320GB/500GB) .

It uses a flash-based web player to stream and show video files. Registered users may upload an unlimited amount of video and build their own personal profile. YouTube claims that its users watch hundreds of millions, and upload hundreds of thousands of videos daily Hitachi simple touch (250GB/320GB) .

Access

The prevalent language for communication on the Internet is English. This may be a result of the origin of the Internet, as well as English's role as a lingua franca. It may also be related to the poor capability of early computers, largely originating in the United States, to handle characters other than those in the English variant of the Latin alphabet Hitachi simple touch (320GB/500GB) .

After English (28% of Web visitors) the most requested languages on the World Wide Web are Chinese (23%), Spanish (8%), Japanese (5%), Portuguese and German (4% each), Arabic, French and Russian (3% each), and Korean (2%). By region, 42% of the world's Internet users are based in Asia, 24% in Europe, 14% in North America, 10% in Latin Americaand the Caribbean taken together, 5% in Africa, 3% in the Middle East and 1% in Australia/Oceania Hitachi life studio (320GB/500GB) .

In Asia, South Korea has the biggest internet penetration with 81.1% users (as comparison Japan with 78.2% and USA with 77.3%[27]). The Internet's technologies have developed enough in recent years, especially in the use of Unicode, that good facilities are available for development and communication in the world's widely used languages Hitachi life studio (250GB/320GB) .

However, some glitches such as mojibake (incorrect display of some languages' characters) still remain.

Common methods of Internet access in homes include dial-up, landline broadband (over coaxial cable, fiber optic or copper wires), Wi-Fi,satellite and 3G technology cell phones Hitachi life studio platinum (250GB/320GB) .

Public places to use the Internet include libraries and Internet cafes, where computers with Internet connections are available. There are also Internet access points in many public places such as airport halls and coffee shops, in some cases just for brief use while standing Hitachi life studio platinum (320GB/500GB) .

Various terms are used, such as "public Internet kiosk", "public access terminal", and "Web payphone". Many hotels now also have public terminals, though these are usually fee-based. These terminals are widely accessed for various usage like ticket booking, bank deposit, online payment etc Hitachi life studio desk (500GB/1TB) .

Wi-Fi provides wireless access to computer networks, and therefore can do so to the Internet itself.Hotspots providing such access include Wi-Fi cafes, where would-be users need to bring their own wireless-enabled devices such as a laptop or PDA. These services may be free to all, free to customers only, or fee-based Hitachi life studio plus (320GB/500GB) .

A hotspot need not be limited to a confined location. A whole campus or park, or even an entire city can be enabled. Grassroots efforts have led to wireless community networks. Commercial Wi-Fi services covering large city areas are in place in London, Vienna, Toronto, San Francisco, Philadelphia, Chicago and Pittsburgh Hitachi life studio plus (320GB/500GB) .

The Internet can then be accessed from such places as a park bench. Apart from Wi-Fi, there have been experiments with proprietary mobile wireless networks like Ricochet, various high-speed data services over cellular phone networks, and fixed wireless services. High-end mobile phones such as smartphones generally come with Internet access through the phone network Hitachi X mobile (250GB/320GB) .

Web browsers such as Opera are available on these advanced handsets, which can also run a wide variety of other Internet software. More mobile phones have Internet access than PCs, though this is not as widely used.[citation needed] An Internet access provider and protocol matrix differentiates the methods used to get online Hitachi X mobile(320GB/500GB) .

Social impact

The Internet has enabled entirely new forms of social interaction, activities, and organizing, thanks to its basic features such as widespread usability and access. Social networking websites such as Facebook, Twitter and MySpace have created new ways to socialize and interact Hitachi XL (1TB/2TB) .

Users of these sites are able to add a wide variety of information to pages, to pursue common interests, and to connect with others. It is also possible to find existing acquaintances, to allow communication among existing groups of people. Sites like LinkedIn foster commercial and business connections. YouTube and Flickr specialize in users' videos and photographs Toshiba canvio portable(320GB/500GB) .

In the first decade of the 21st century the first generation is raised with widespread availability of Internet connectivity, bringing consequences and concerns in areas such as personal privacy and identity, and distribution of copyrighted materials. These "digital natives" face a variety of challenges that were not present for prior generations Toshiba canvio portable(750GB/1TB) .

The Internet has achieved new relevance as a political tool, leading to Internet censorship by some states. The presidential campaign of Howard Dean in 2004 in the United States was notable for its success in soliciting donation via the Internet. Many political groups use the Internet to achieve a new method of organizing in order to carry out their mission Toshiba anvio for Mac(500GB/750GB) ,

having given rise to Internet activism. Some governments, such as those of Iran, North Korea, Myanmar, the People's Republic of China, and Saudi Arabia, restrict what people in their countries can access on the Internet, especially political and religious contentToshiba canvio for Mac(750GB/1TB) .

This is accomplished through software that filters domains and content so that they may not be easily accessed or obtained without elaborate circumvention.

In Norway, Denmark, Finland and Sweden, major Internet service providers have voluntarily, possibly to avoid such an arrangement being turned into law, agreed to restrict access to sites listed by authorities. While this list of forbidden URLs is only supposed to contain addresses of known child pornography sites, the content of the list is secret Toshiba External HDD –portable(320GB/500GB) .

Many countries, including the United States, have enacted laws against the possession or distribution of certain material, such as child pornography, via the Internet, but do not mandate filtering software Toshiba portable(500GB/640GB) .