How many computers were linked together at first?

Answer 1

One of the first "networks" that lead to the internet was the ARPANET in august of 1962 it was created, and the first node (point) on it was University California Las Angeles (UCLA) on September 2nd, 1969. It then moved through Stanford Research institute, University of California Santa Barbara, and through the University of Utah's Graphics Department. This is the growth of ARPANET (as taken from http://en.wikipedia.org/wiki/ARPANET)

"In March, 1970, the ARPANET reached the U.S. East Coast, when an IMP at BBN itself was joined up to the network. Thereafter, the network grew quickly: 9 IMPs by June of 1970, and 13 by December; 18 by September, 1971 (at which point twenty-three hosts, at universities and government research centers, were connected to the ARPANET); 29 by August, 1972, and 40 by September, 1973. At that point, two satellite links, across the Pacific and Atlantic Oceans to Hawaii and Norway (Norwegian Seismic Array) respectively, had been added to the network. From Norway, a terrestrial circuit added an IMP in London to the growing network. By June 1974, there were 46 IMPs, and the network reached 57 in July, 1975. By 1981, the number of hosts had grown to 213, with a new host being added approximately every twenty days. After the ARPANET had been up and running for several years, ARPA looked for another agency to hand off the network to; ARPA's primary business was funding cutting-edge research and development, not running a communications utility. Eventually, in July 1975, the network was turned over to the Defense Communications Agency, also part of the Department of Defense. In 1983, the U.S. military portion of the ARPANet was broken off as a separate network, the MILNET. Prior to this there were 113 nodes on the ARPANet. After the split, that number was 45 nodes with the remainder moving to MILNET."
The idea of an internet came from Xerox Network Services (yes the Xerox we know of today!) when they worked toward making a standard we know of today called TCP/IP (Transmission Control Protocol/Internet Protocol)

In 1973, Norway followed suit and made the NORSAR, and ARPANET made a connection. Later on that year, these we transformed to the TCP/IP and this protocol became standard to the internet we know of today.
Since the commerical use of ARPANET was forbidden, the exact definition of commerical use was so unclear, UUCPNET became formed and connect to ARPANET, due to administrators "casting a blind eye" onto their connections. Larger companies began using UUCPNET and in the 1980s, dialup on the west coast was formed by companies like UUNET, PSINET, NETCOM, and Portal Software. In 1986 a company on the east coast began providing dial up access to UUCPNET and this company was called world.std.com. This was the beginning of the internet.