there are two routes in and out of your computer. One is MIDI which sends and receives signals to trigger instruments, sequencers, and other things to play. The other is audio, live sound coming out of and into your sound card. Most computers wil have a line in and a line out just look in the back. With Midi it needs a special device to send in and out of the computer called a MIDI I/O or whatever. Macs come already with one but PCs wil require something to plug into either a USB port or another I/O paralell or serial.
Theres a whole other world of tape sync and stuff that I don't know much about ADATs etc......theres lots of information/tutorials on the web for beginning computer recording.....try homerecording.com and go from there............
