Can someone explain record releasing?

I know that a band releses an album and then releases singles off of that, but how does it work, really? What is the process? How many singles need to be released off an album and what not.. and what about EPs? Like Mellowdrone doesnt have any albums yet, they have just been.. releasing stuff!

I'm curious here, and don't bitch at me, I did google it and found nothing.

Thanks~