Internet

The Internet is the global system of interconnected that uses the (TCP/IP) to communicate between networks and devices. It is a network of networks that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries a vast range of information resources and services, such as the inter-linked documents and of the (WWW), , , and .

The origins of the Internet date back to the development of and research commissioned by the in the 1960s to enable of computers., initially served as a backbone for interconnection of regional academic and military networks in the 1970s. The funding of the as a new backbone in the 1980s, as well as private funding for other commercial extensions, led to worldwide participation in the development of new networking technologies, and the merger of many networks. and generated a sustained exponential growth as generations of institutional, , and were connected to the network. Although the Internet was widely used by in the 1980s, incorporated its services and technologies into virtually every aspect of modern life.

Most traditional communication media, including telephony, radio, television, paper mail and newspapers are reshaped, redefined, or even bypassed by the Internet, giving birth to new services such as , , , , digital newspapers, and websites. Newspaper, book, and other print publishing are adapting to technology, or are reshaped into , and online . The Internet has enabled and accelerated new forms of personal interactions through , , and . has grown exponentially both for major retailers and and , as it enables firms to extend their "" presence to serve a larger market or even . and on the Internet affect across entire industries.

The Internet has no single centralized governance in either technological implementation or policies for access and usage; each constituent network sets its own policies. in the Internet, the (IP address) space and the (DNS), are directed by a maintainer organization, the (ICANN). The technical underpinning and standardization of the core protocols is an activity of the (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise.'s list of .[6]

When the term Internet is used to refer to the specific global system of interconnected (IP) networks, the word is a according to the . In common use and the media, it is often not capitalized, viz. the internet. Some guides specify that the word should be capitalized when used as a noun, but not capitalized when used as an adjective. The designers of early computer networks used internet both as a noun and as a verb in shorthand form of or internetworking, meaning interconnecting computer networks.

The terms Internet and World Wide Web are often used interchangeably in everyday speech; it is common to speak of "going on the Internet" when using a to view . However, the or the Web is only one of a large number of Internet services. The Web is a collection of interconnected documents (web pages) and other , linked by and . is a of Internet and World Wide Web typically used sarcastically to parody a technically unsavvy user.

The (ARPA) of the United States Department of Defense funded research into of computers in the 1960s., one of the fundamental Internet technologies, started in the work of in the early 1960s and, independently, in 1965. Packet switching was incorporated into the proposed design for the in 1967 and other packet-switched networks such as the , the , and which were developed in the late 1960s and early 1970s.[19]

ARPANET development began with two network nodes which were interconnected between the Network Measurement Center at the (UCLA) directed by , and the NLS system at (SRI) by in , California, on 29 October 1969., followed by the Graphics Department. In a sign of future growth, fifteen sites were connected to the young ARPANET by the end of 1971. These early years were documented in the 1972 film .

Early international collaborations for the ARPANET were rare. Connections were made in 1973 to the Norwegian Seismic Array () via a satellite station in , Sweden, and to 's research group at which provided a gateway to British academic networks. The ARPANET project and led to the development of various and standards by which multiple separate networks could become a single network or "a network of networks". and used the term internet as a shorthand for in   and later repeated this use. with important influences on design. providers were concerned with developing .[28]

Access to the ARPANET was expanded in 1981 when the (NSF) funded the (CSNET). In 1982, the (TCP/IP) was standardized, which permitted worldwide proliferation of interconnected networks. TCP/IP network access expanded again in 1986 when the (NSFNet) provided access to sites in the United States for researchers, first at speeds of 56 kbit/s and later at 1.5 Mbit/s and 45 Mbit/s. had global reach well before this time, this marked the beginning of the Internet as an intercontinental network. Commercial (ISPs) emerged in 1989 in the United States and Australia.[34] The ARPANET was decommissioned in 1990.

(ISPs) establish the worldwide connectivity between individual networks at various levels of scope. End-users who only access the Internet when needed to perform a function or obtain information, represent the bottom of the routing hierarchy. At the top of the routing hierarchy are the , large telecommunication companies that exchange traffic directly with each other via very high speed and governed by agreements. and lower level networks buy from other providers to reach at least some parties on the global Internet, though they may also engage in peering. An ISP may use a single upstream provider for connectivity, or implement to achieve redundancy and load balancing. are major traffic exchanges with physical connections to multiple ISPs. Large organizations, such as academic institutions, large enterprises, and governments, may perform the same function as ISPs, engaging in peering and purchasing transit on behalf of their internal networks. Research networks tend to interconnect with large subnetworks such as , , , and the UK's , . Both the Internet IP routing structure and hypertext links of the World Wide Web are examples of . (for: unclear whether citation supports claim empirically) ] Computers and use in their operating system to to the next-hop router or destination. Routing tables are maintained by manual configuration or automatically by . End-nodes typically use a that points toward an ISP providing transit, while ISP routers use the to establish the most efficient routing across the complex connections of the global Internet.

An estimated 70 percent of the world's Internet traffic passes through , .

Access

Common methods of by users include dial-up with a computer via telephone circuits, over , or copper wires, , , and technology (e.g. ). The Internet may often be accessed from computers in libraries and . exist in many public places such as airport halls and coffee shops. Various terms are used, such as public Internet kiosk, public access terminal, and Web . Many hotels also have public terminals that are usually fee-based. These terminals are widely accessed for various usages, such as ticket booking, bank deposit, or online payment. Wi-Fi provides wireless access to the Internet via local computer networks. providing such access include , where users need to bring their own wireless devices such as a laptop or . These services may be free to all, free to customers only, or fee-based.

efforts have led to . Commercial Wi-Fi services that cover large areas are available in many cities, such as , , , , , , and , where the Internet can then be accessed from places such as a park bench., various high-speed data services over cellular networks, and fixed wireless services. Modern can also access the Internet through the cellular carrier network. For Web browsing, these devices provide applications such as , , and and a wide variety of other Internet software may be installed from app-stores. Internet usage by mobile and tablet devices exceeded desktop worldwide for the first time in October 2016.[63]

Mobile communication

The (ITU) estimated that, by the end of 2017, 48% of individual users regularly connect to the Internet, up from 34% in 2012. connectivity has played an important role in expanding access in recent years especially in and in . As of 2016, almost 60% of the world's population had access to a ].. Fragmentation restricts access to media content and tends to affect poorest users the most.[65]

, the practice of allowing users free connectivity to access specific content or applications without cost, has offered opportunities to surmount economic hurdles, but has also been accused by its critics as creating a two-tiered Internet. To address the issues with zero-rating, an alternative model has emerged in the concept of 'equal rating' and is being tested in experiments by and in . Equal rating prevents prioritization of one type of content and zero-rates all content up to a specified data cap. A study published by , 15 out of 19 countries researched in had some kind of hybrid or zero-rated product offered. Some countries in the region had a handful of plans to choose from (across all mobile network operators) while others, such as , offered as many as 30 pre-paid and 34 post-paid plans.[67]

A study of eight countries in the found that zero-rated data plans exist in every country, although there is a great range in the frequency with which they are offered and actually used in each., , and , found 's Free Basics and to be the most commonly zero-rated content.[69]

The Internet standards describe a framework known as the (also called , based on the first two components.) This is a model architecture that divides methods into a , originally documented in   1123.

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