On the Internet and internets



A word on "the Internet," and on "internets" in general, is in order. In print, the difference between the two seems slight: one is always capitalized, one isn't.

The distinction between their meanings, however, is significant. The Internet, with a capital "I," refers to the network that began its life as the ARPAnet and continues today as, roughly, the confederation of all TCP/IP networks directly or indirectly connected to commercial U.S. backbones.
Seen close up, it's actually quite a few different networks - commercial TCP/IP backbones, regional TCP/IP networks, corporate and U.S. government TCP/IP networks, and TCP/IP networks in other countries - interconnected by high-speed digital circuits.

A lowercase internet, on the other hand, is simply any network made up of multiple smaller networks using the same internetworking protocols. An internet (little "i") isn't necessarily connected to the Internet (big "I"), nor does it necessarily use TCP/IP as its internetworking protocol. There are isolated corporate internets, and there are Xerox XNS-based internets and DECnet-based internets.

The new term "intranet" is really just a marketing term for a TCP/IP-based "little i" internet, used to emphasize the use of technologies developed and introduced on the Internet within a company's internal corporate network. An "extranet," on the other hand, is an internet that connects partner companies, or a company to its distributors, suppliers, and customers.


Odlomek je iz knjige ("biblije" DNS) DNS and BIND