homealone

you are most likely already using one if you have broadband from NTL

click on this link

http://www.cableforum.co.uk/board

then on the 'connection' link in the top menu bar and it will tell you.

Basically the cache server holds a copy of the most commonly requested pages, so when you click on a page link, you get the copy.

Sometimes this 'automatic' caching doesn't work, resulting in pages not loading - in this case choosing to set another proxy server as the explicit cache, can often solve the problem. The link to Robin Walkers site Paul posted above has more info.