Internet

The Internet (note the capital 'I'; just as there are 'white houses', but only one 'White House', there are many 'internets', but only one 'Internet') is an internet (the short form of the term internetwork) which is the world's dominant information network.

It uses the TCP/IP protocol suite for communication.

It is to some degree a direct descendant of the ground-breaking ARPANET, but only in the sense that its early dominant application protocols (TELNET, FTP, and email) were direct clones of those of the ARPANET; and that the technical community which created it was an overlap/descendant of the one which produced the ARPANET. (See the TCP/IP article for more on TCP/IP's antecedants.)