In the general sense, an internet (with a lowercase “i”, a shortened form of the original inter-network) is a computer network that connects several networks. As a proper noun, the Internet is the publicly available internationally interconnected system of computers (plus the information and services they provide to their users) that uses the TCP/IP suite of packet switching communications protocols. Thus, the largest internet is called simply “the” Internet. The art of connecting networks in this way is called internetworking.
The core networks forming the Internet started out in 1969 as the ARPANET devised by the United States Department of Defense Advanced Research Projects Agency (ARPA).
Some early research which contributed to ARPANET included work on decentralised networks (including damage survivability) , queueing theory and packet switching.
On January 1, 1983, the ARPANET changed its core networking protocols from NCP to the then-new TCP/IP, marking the start of the Internet as we know it today.
Another important step in the development was the National Science Foundation’s (NSF) building of a university backbone, the NSFNet, in 1986. Important disparate networks that have successfully been accommodated within the Internet include Usenet, Fidonet, and Bitnet.
During the 1990s, the Internet successfully accommodated the majority of previously existing computer networks. This growth is often attributed to the lack of central administration, which allows organic growth of the network, as well as the non-proprietary nature of the internet protocols, which encourages vendor interoperability and prevents one company from exerting control over the network.
The Internet is held together by bi- or multilateral commercial contracts (for example peering agreements) and by technical specifications or protocols that describe how to exchange data over the network. These protocols are formed by discussion within the Internet Engineering Task Force (IETF) and its working groups, which are open to public participation and review. These committees produce documents that are known as Requests For Comments (RFCs). Some RFCs are raised to the status of Internet Standard by the Internet Architecture Board (IAB). Some of the most used protocols in the Internet protocol suite are IP, TCP, UDP, DNS, PPP, SLIP, ICMP, POP3, IMAP, SMTP, HTTP, HTTPS, SSH, Telnet, FTP, LDAP, and SSL.
Some of the popular services on the Internet that make use of these protocols are e-mail, Usenet newsgroups, file sharing, the World Wide Web, Gopher, session access, WAIS, finger, IRC, MUDs, and MUSHs. Of these, e-mail and the World Wide Web are clearly the most used, and many other services are built upon them, such as mailing lists and web logs. The internet makes it possible to provide real-time services such as web radio and webcasts that can be accessed from anywhere in the world.
Some other popular services of the Internet were not created this way, but were originally based on proprietary systems. These include ICQ, AIM, CDDB, and Gnutella.
There have been many analyses of the Internet and its structure. For example, it has been determined that the Internet IP routing structure and hypertext links of the World Wide Web are examples of scale-free networks.
The Internet has a large and growing number of users that have created a distinct culture, Internet dynamics. see Netiquette, Internet friendship, Trolls and trolling, Flaming, Cybersex, Hacktivism or Hacker culture, Internet humor, Internet slang, and Internet art.
The most used language for communications on the Internet is English, due to the Internet’s origins, to its use commonly in software programming, to the poor capability of early computers to handle characters other than western alphabets.
The net has grown enough in recent years, though, that sufficient native-language content for a worthwhile experience is available in most developed countries. However, some glitches such as mojibake still remain troublesome for Internet users.
The proliferation of the Internet caused vast impacts in the society. Instances include copyright issues, issues concerned with free speech such as pornography and hatred. In response to that situation, lately cyber laws have been created and enforced. Many discussions have raged over the question of how states should interact with telecommunication tools including the Internet.
Countries with the best internet access include South Korea (50% of the population has broadband access) and Sweden, according to “Web-savviest nation”.
Public places to use Internet include libraries and Internet cafes, where computers with internet connection are available. There are also internet access points in public places like airport halls, sometimes just for brief use while standing. Various terms are used, such as “public Internet kiosk”, “public access terminal”.
Alternatively there are Wifi-cafes (“hotspots”), where one needs to bring one’s own wifi-enabled notebook or PDA, for which the cafe provides wireless access to the Internet.
The services may be free (possibly in connection with paid services such as buying coffee) or for a fee (metered access or with a pass for e.g. a day or month).
A hotspot may also be larger, e.g. including the piece of street in front of the library, a whole street, a campus including outdoor areas, a town part or, as is under construction in some places, a whole town; see also Metropolitan area network, Wireless community network.
Advantages of using one’s own computer include more upload and download possibilities, using one’s favorite browser and browser settings (the preferences menu may be disabled in a public computer), and integrating activities on internet and on one’s own computer, using one’s own programs and data. (Using public computers one can use one’s email box as storage area for data. For programs one may do the same, but the size of the mailbox and restrictions on the public computer limit the possibilities of running one’s own programs.)