Some "purists" might frown on different types of music software, but it is incredible how easily one can assemble a sophisticated studio with some good software.
Take amp modelers, for example. Those allow, say, a guitarist to plug into a computer, bang out a few chords or leads and dial in the desired sound. There are modelers that emulate Marshall stacks, Fender Twin Reverb amps, Vox AC-30s (for the Beatles sound) and just about anything else you can imagine. A good amp modeler, then, will give a guitarist access to an almost endless array of amps and effects -- equipment that would cost a fortune if a guitarist set out to buy the "real" stuff.
For a home recorder wanting to make some demos that sound great, what on earth could be better than that?