The "Internet" or "World Wide Web" is a network of connected computers - from yours - to mine - to anyone else's via an "ISP" (Internet Service Provider), that you pay, either directly or indirectly for the privilege. Some providers are free, but they get a cut from the phone company, others currently charge £15.99 GBP or so, per month, to let you connect to them via your phone line, without getting any extra call charges. Broadband (currently about £29.99 GBP per month) is a much faster connection with higher "Bandwidth" - think of it as a water pipe, the bigger the pipe the faster the flow!

For this wonderful thing to exist, all the networking protocol types need to be robust. On early networks, running with various different protocols, if you lost a connection, then simply reconnecting did not work. Much messing about was required!

So along comes "TCP" - ("Transmission Control Protocol") & IP" - (Internet Protocol) - both are used to guarantee accurate end to end delivery of segments of data, to put out of order segments in order, and to generally keep the whole thing running smoothly.

TCP and IP were developed by a the American Department of Defense research project to connect a number different networks designed by different manufacturers into a larger network of computers (the "Internet"). On the battlefield a communications network will sustain damage, so the system was designed to be robust and automatically recover from any node or phone line failure. This design allows the construction of very large networks with less central management. It was initially successful because it delivered a few basic services that everyone needs (file transfer, electronic mail, remote logon) across a very large number of client and server systems. Several computers in a small department can use TCP/IP (along with other protocols) on a single LAN - (Local Area Network) . The IP component provides routing from the user to the service provider, then to regional networks, and finally to the global Internet.

All this is of course done by a sequence of numbers, so to make it a usable proposition for the everyday "surfer" the numbers are converted to names at your PC without you having to know what they are, & also at the service provider's end on their DNS servers, (Domain Name System) so you can type in your preferred language & find your way around the net. The Domain Name System (DNS) is a distributed Internet directory service. DNS is used mostly to translate between domain names and IP addresses, and to control Internet email delivery. Most Internet services rely totally on DNS to work, and if their DNS fails, web sites cannot be located and email delivery stalls!