This is going to make me sound like a complete noob, but I searche bar'd it and it didn't really answer my question.

Anyway, I'm considering buying a loop station since my band has no second guitarist and I'd like to have a back-up track so I can practice soloing. I know you flip the switch, play as it records what you want, and then it plays what you've "recorded" <--I really don't know if that's how it works or not.

But the question is, it plays through the amp, right? Or do I need to get an external speaker? And How does it actually work.

Thanks UG, it's much appreciated.

PS: In b4 obvious troll, I'm dead serious, I don't know a thing about this stuff
You use the same amp, and I think it's a reasonable question. They work by tracking what you're playing and once you step on the footswitch it ends that recording and plays it back, again and again and again...
Depending on which looper you have you can do multitrack recording and sample them all together.

It might be a bit difficult to use in a band situation as a replacement guitarist, so that could be tricky - you'd need to play the second part before hand or play the part as you record and then while it loops play the second guitar - more that I'm capable of.
I don't know much about them.. never used but one thing is make sure you have an effects loop otherwise the looped and your guitar signal will distort thus sounding like crap.. unless you use a pedal distortion then it's ok..

but if you do have 2 amps you can loop it on one and play on the other I think.