It depends on what's inside it. An 'internet' is a collection of disparate networks tied together with packet switches which examine the internet-layer headers of the packets passing through them (such boxes are now known as 'routers'). The "internet layer" doesn't appear in the ISO 7-layer model, since the concept didn't appear until after that was done; but you can imagine it as layer '3A', crammed in between 3 ('Network') and 4 ('Transport'). Note that there are a number of networking protocol families that include the internet concept; CHAOS, PUP, XNS and DECnet among them (although there are several versions of DECnet and I no longer remember the details of most of them, so take that one with the proverbial grain, but several had internets). Does does the network in your house use router(s) to tie it together? If so, it's an internet; if not, no. If you have a wireless hub, connected to a CATV modem, you probably have a small piece of 'the Internet' in your house. (See below.) Note that there are still internets (and networks) which are not connected to the Internet - Google for "air gap". Originally 'the Internet' was the large TCP/IP internet centered around the ARPANET, and later the NSFNET. These days, the concept is more diffuse - there was some discussion recently on the internet-history list: http://mailman.postel.org/pipermail/internet-history/ about it, but I'm too lazy to track down the exact messages. Noel