is simply a computer that handles requests from other computers - it 'serves' them what they want.
A normal PC can act as a perfectly adequate server, provided it isn't stressed too highly. To be an efficient server a machine must be capable of handling a large number or requests simultaneously, and for this it will need a fast processor (or more typically processors), a large, fast hard drive or drives and lots of RAM. It will also need to run an efficient, dependable and stable operating system.
Don't know what to say! Such generous and knowledgeable contribtuions. I don't have any further questions at the moment as I need time to digest all this. I tend to think in human terms about the workings of computers. EG. a h/d is like some sort of store/ used to be drawer when they used to be 10g/15g and defragmenting is like stock taking and so on. I found this easier for people to understand when they asked me questions. Thank you all.
Just have another thought. In a domestic situation it would be easier to network using say my adsl modem router than a server. With wireless networking advancing fast would it mean that servers are becoming redundant? I suppose the advantage of servers over router networking is that the former can connect up more devices. Am I correct in this assumption?