ADVANCED RESEARCH PROJECT AGENCY (ARPA)
The efforts of ARPA was to active all its research groups have accept to new era computers. For this purpose ARPA started investing in ways to do data networking ARPA use a new approach consisting of internetworking and packet switching to fulfill the principle of source sharing. As a result of ARPA discovery the first network was established which was named ARPANET. In that way the internet was emerged in 1970's and it has started drastically since then as given in the figure below.