I have a few queston about home recording..........

Ive always used my computer to record but im getting fed up with the sound quality so ive decided to get some better gear.

First offf

well uhmm, how is an eight track really used? im confused about that does it go onto the computer or is into memory?

and i dont wanna record using tape so i figured like an eight track would be the way to go but i dont fully understand that whole thing as it is so how do you use these and what would be a good cheap system to use?

also when using condenser mics what exactly is the preamp do and is it like needed to use condenser mics? Can i play through a tube amp instead?