international computer network linking together thousands of individual networks at military and government agencies, educational institutions, nonprofit organizations, industrial and financial corporations of all sizes, and commercial enterprises (called gateways or service providers) that enable individuals to access the network. The most popular features of the Internet include electronic mail (e-mail), discussion groups (called newsgroups or bulletin boards, where users can post messages and look for responses on a system called Usenet ), on-line conversations (called chats), adventure and role-playing games, information retrieval, and electronic commerce ( e-commerce ). The public information stored in the multitude of computer networks connected to the Internet forms a huge electronic library, but the enormous quantity of data and number of linked computer networks also make it difficult to find where the desired information resides and then to retrieve it. A number of progressively easier-to-use interfaces and tools have been developed to facilitate searching. Among these are search engines, such as Archie, Gopher, and WAIS (Wide Area Information Server), and a number of commercial indexes, which are programs that use a proprietary algorithm to search a large collection of documents for keywords and return a list of documents containing one or more of the keywords. Telnet is a program that allows users of one computer to connect with another, distant computer in a different network. The File Transfer Protocol (FTP) is used to transfer information between computers in different networks. The greatest impetus to the popularization of the Internet came with the introduction of the World Wide Web (WWW), a hypertext system that makes browsing the Internet both fast and intuitive. Most e-commerce occurs over the Web.

Each computer that is directly connected to the Internet is uniquely identified by a 32-bit binary number called its IP address. This address is usually seen as a four-part decimal number, each part equating to 8 bits of the 32-bit address in the decimal range 0-255. Because an address of the form 4.33.222.111 could be difficult to remember, a system of Internet addresses, or domain names, was developed in the 1980s. Reading from left to right, the parts of a domain name go from specific to general. For example, www.irs.ustreas.gov is a World Wide Web site at the Internal Revenue Service, which is part of the U.S. Treasury Dept., which is a government agency. The rightmost part, or top-level domain (or suffix or zone), can be a two-letter abbreviation of the country in which the computer is in operation; more than 250 abbreviations, such as “ca” for Canada and “uk” for United Kingdom, have been assigned. Although such an abbreviation exists for the United States (us), it is more common for a site in the United States to use a three-letter, specialized top-level domain such as edu (educational institution), gov (government), or mil (military) or one of the four domains designated for open registration worldwide, com (commercial), int (international), net (network), or org (organization). In 2000 seven additional top-level domains were approved for worldwide use. An Internet address is translated into an IP address by a domain-name server, a program running on an Internet-connected computer.

The Internet evolved from a secret feasibility study conceived by the U.S. Dept. of Defense in 1969 to test methods of enabling computer networks to survive military attacks, by means of the dynamic rerouting of messages. As the ARPAnet (Advanced Research Projects Agency network), it began by connecting three networks in California with one in Utah—these communicated with one another by a set of rules called the Internet Protocol (IP). By 1972, when the ARPAnet was revealed to the public, it had grown to include about 50 universities and research organizations with defense contracts, and a year later the first international connections were established with networks in England and Norway. A decade later, the Internet Protocol was enhanced with a set of communication protocols, the Transmission Control Program/Internet Protocol (TCP/IP), that supported both local and wide-area networks. Shortly thereafter, the National Science Foundation (NSF) created the NSFnet to link five supercomputer centers, and this, coupled with TCP/IP, soon supplanted the ARPAnet as the backbone of the Internet. In 1995, however, the NSF decommissioned the NSFnet, and responsibility for the Internet was assumed by the private sector. Fueled by the increasing popularity of personal computers, e-mail, and the World Wide Web (which was introduced in 1991 and saw explosive growth beginning in 1993), the Internet became a significant factor in the stock market and commerce during the second half of the decade. By 2000 it was estimated that the number of adults using the Internet exceeded 100 million in the United States alone.

הנה עוד אחד :

Internet, the


international computer network linking together thousands of individual networks at military and government agencies, educational institutions, nonprofit organizations, industrial and financial corporations of all sizes, and commercial enterprises (called gateways or service providers) that enable individuals to access the network. The most popular features of the Internet include electronic mail (e-mail), discussion groups (called newsgroups or bulletin boards, where users can post messages and look for responses on a system called Usenet), on-line conversations (called chats), adventure and role-playing games, information retrieval, and electronic commerce (e-commerce). 1
The public information stored in the multitude of computer networks connected to the Internet forms a huge electronic library, but the enormous quantity of data and number of linked computer networks also make it difficult to find where the desired information resides and then to retrieve it. A number of progressively easier-to-use interfaces and tools have been developed to facilitate searching. Among these are search engines, such as Archie, Gopher, and WAIS (Wide Area Information Server), and a number of commercial indexes, which are programs that use a proprietary algorithm to search a large collection of documents for keywords and return a list of documents containing one or more of the keywords. Telnet is a program that allows users of one computer to connect with another, distant computer in a different network. The File Transfer Protocol (FTP) is used to transfer information between computers in different networks. The greatest impetus to the popularization of the Internet came with the introduction of the World Wide Web (WWW), a hypertext system that makes browsing the Internet both fast and intuitive. Most e-commerce occurs over the Web. 2
Each computer that is directly connected to the Internet is uniquely identified by a 32-bit binary number called its IP address. This address is usually seen as a four-part decimal number, each part equating to 8 bits of the 32-bit address in the decimal range 0-255. Because an address of the form 4.33.222.111 could be difficult to remember, a system of Internet addresses, or domain names, was developed in the 1980s. Reading from left to right, the parts of a domain name go from specific to general. For example, www.irs.ustreas.gov is a World Wide Web site at the Internal Revenue Service, which is part of the U.S. Treasury Dept., which is a government agency. The rightmost part, or top-level domain (or suffix or zone), can be a two-letter abbreviation of the country in which the computer is in operation; more than 250 abbreviations, such as “ca” for Canada and “uk” for United Kingdom, have been assigned. Although such an abbreviation exists for the United States (us), it is more common for a site in the United States to use a three-letter, specialized top-level domain such as edu (educational institution), gov (government), or mil (military) or one of the four domains designated for open registration worldwide, com (commercial), int (international), net (network), or org (organization). In 2000 seven additional top-level domains were approved for worldwide use. An Internet address is translated into an IP address by a domain-name server, a program running on an Internet-connected computer. 3
The Internet evolved from a secret feasibility study conceived by the U.S. Dept. of Defense in 1969 to test methods of enabling computer networks to survive military attacks, by means of the dynamic rerouting of messages. As the ARPAnet (Advanced Research Projects Agency network), it began by connecting three networks in California with one in Utah—these communicated with one another by a set of rules called the Internet Protocol (IP). By 1972, when the ARPAnet was revealed to the public, it had grown to include about 50 universities and research organizations with defense contracts, and a year later the first international connections were established with networks in England and Norway. A decade later, the Internet Protocol was enhanced with a set of communication protocols, the Transmission Control Program/Internet Protocol (TCP/IP), that supported both local and wide-area networks. Shortly thereafter, the National Science Foundation (NSF) created the NSFnet to link five supercomputer centers, and this, coupled with TCP/IP, soon supplanted the ARPAnet as the backbone of the Internet. In 1995, however, the NSF decommissioned the NSFnet, and responsibility for the Internet was assumed by the private sector. Fueled by the increasing popularity of personal computers, e-mail, and the World Wide Web (which was introduced in 1991 and saw explosive growth beginning in 1993), the Internet became a significant factor in the stock market and commerce during the second half of the decade. By 2000 it was estimated that the number of adults using the Internet exceeded 100 million in the United States alone.

הנה עוד קצת :

Internet
From Wikipedia, the free encyclopedia.

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 creation of the Internet
Main article: History of the Internet
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. See History of the Internet.

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.

Today's Internet
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 IRC, 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.

Internet culture
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 Internet is also having a profound impact on knowledge and worldviews. Through keyword-driven Internet research, using search engines, like Google, millions worldwide have easy, instant access to a vast amount and diversity of online information. Compared to books and traditional libraries, the Internet represents a sudden and extreme decentralization of information and data.

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.

Internet politics
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.

Internet access
Countries with the best internet access include South Korea (50% of the population has broadband access) and Sweden, according to "Web-savviest nation".

Dial-up access
Broadband access

Public places to use the Internet
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", "web payphone".
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.)