I know this will get a reaction - it's basically accurate even if not 100% true.
they are the same thing ... like a memory stick and usb key ... or hoover and dyson.
now for the lies ;-)
set a budget ... and stick with it.
the market is so cutthroat that �400 will buy pretty much the same in terms of performance.
however - to qualify different manuf
some will have bigger screen, or hard discs ... dvd writers, more RAM
so you need to read the spec ...
more of one generally means less of another (within a price range) ...
get a look at a couple of mags ... see what they say
but most of all - stick to your budget