In 1969 it all began as the ARPAnet, a link between 4 computers of the of the Advanced Research Projects Agency (a branch of the United States Department of Defense). These four computers were at University of Utah, The University of California at Santa Barbara, The University of California at Los Angeles and, The Stanford Research Institute. As time went by, other computers were added and by 1981, the number of computers on the ARPAnet had grown from 4 to 213. In late 1990, it was more like 313,000. Originally the ARPAnet used an early version of Network Control Protocol (NCP) but in 1974, TCP (Transfer Control Protocol) was described in a paper by Kahn and Cerf. In 1977, TCP was introduced for cross-network connections and it slowly began to replace NCP because it was faster, easier to use, and a lot less expensive to implement. TCP breaks up the messages or data into a series of short packages or packets whose length is defined by the (packet-switched) network. The most important benefit of this is speed as the packets are short and the communication links between the nodes are only allocated to transferring each single message for a short period of time. TCP does not require the communication links between the nodes to be dedicated between the transmission of each packet of data. Instead, the packets, each with its own temporary header, are individually sent, received and, reassembled into the larger message, once the temporary headers are deleted. TCP is connection-oriented, stream-oriented and, provides for reliable communication over packet-switched networks. In 1978 IP (Internet Protocol) was added to TCP and this new protocol took over the task of routing the messages. On January 01, 1983, every site within or connected to the ARPAnet was supposed to switch to TCP/IP. Some of the sites were given a grace period of a few months but, by the spring, all systems that were not changed over were bumped off the network. By this time, the networking community had begun to call the ARPAnet and its affiliated networks the "Internet" and later in 1983, this name became official. There were 562 connections in the summer of that year. In 1989, Tim Berners Lee at CERN (Conseil Europeen pour la Recherche Nucleaire), the European Laboratory for Nuclear Research in Geneva, Switzerland, first coined the term the Web to define an information systems project which ended up spanning the globe. Today the World Wide Web is the hypermedia-based system for browsing Internet sites. It was named the Web because it was made of many sites linked together. Users could travel from one site to another by clicking on hyperlinks and text, graphics, sound and, video could all be accessed with browser programs like Mosaic®, Netscape®, Mozilla® or, Internet Explorer®. There were however no web browser programs at the time. The Web commonly uses a client-server concept called HyperText Transfer Protocol or HTTP. Each Web site runs a server program that responds to requests from clients (browser programs). The servers do not keep track of the origin of the requests as they merely pass on the desired resources and they regard each request as a new one. There are also other common kinds of transfer protocols such as FTP or File Transfer Protocol (FTP) which is a method of transferring files between a local computer and a server when an account number and password are known. In 1990, the ARPAnet ceased to exist. In 1993, the NCSA (National Center for Supercomputing Applications, a research center at The University of Illinois at Champaign/Urbana, released Mosaic®, the very first web browser program. This browser allowed individuals to navigate through a very large volume of information and contribute to it irrespective of the size or influence of the organization or the individual concerned. It finally put everyone on an equal footing. The number of domain names (web sites) on the Internet was estimated at 3,212,000 in the summer of 1994 when Stewart-Hay Associates first logged on and this estimate jumped to 6,642,000 a year later. Since then, connections to the Internet have grown at a tremendous rate. In July of 2009, it was estimated that there were more than 681,000,000 web sites. That's more than 212 times what was available in the summer of '94! A billion (US) web sites is not that far away.