5.1 is broken down:
- 2 x fronts (left/right of the TV)
- 1 x center (above or below the TV)
- 2 x rear (behind the couch)
- 1 x sub-woofer anywhere in the room (the .1 part since it's not an amplified channel)
6.1? Not common
7.1 (the new standard, but likely overkill):
- 2 x fronts
- 1 x center
- 2 x surround (on the side, left surround/LS and right surround/RS)
- 2 x rear (beind the cound, left back/LB and right back/RB)
- 1 x sub-woofer
Sometimes you'll see a .2 designation. This means that there are two sub-woofer channels: left and right. This is arguably not important since people can't spatially recognize "where" bass is coming from. There are other surround modes: 9.1, 10.1, 11.1, 10.2, 7.2, etc.
As for the term "satellite", this is a common term for speaker systems like Bose, but not necessarily when you're building a bigger setup.