I think 'Valve' and 'Tube' are simply British and American words for the same thing, (although I could be wrong on that, anybody?)
I'm assuming you know what a valve amp is and that that's answered your question, but I can give you more details if you need.
Out of interest, what do you mean by "regular"? The only other kind of amp (at least that I'm aware of) is a Solid-state, (or transistor). These have become increasingly popular over the years due to their price and reliability, (and I must admit, they're starting to catch up on tone compared to valve's too).
Hope that's of some use.
Don't worry too much about me, ignore me long enough and I'll go away.
