Range

A friend of mine tried to explain the concept of range to me today. As I understand it, the idea is that it is generally impossible to put an opponent on any one hand so you should try to figure out the range of hands that they could possibly have. If you can beat more hands in their range than not you should call their bet, and if not you should fold. Am i understanding this correctly? And is there any way to get good at this other than the obvious (play lots of hands and watch how people play different cards)?

Yes you are understanding this concept.

Playing lots of hands, and watching people (getting reads as to what type of cards they play) is the best way to practice. Reviewing hand histories and understanding position will help too.

Some examples:

Someone with a VPIP of 5% is probably only playing AA, KK, QQ, AK.

A small stack in a SNG, with an M of 2 that pushes all in, well his range is so big that calling in the BB whens it's folded to you with a K9o isn't all that bad.

What I've done in the past is watch all hands, even ones that I'm not involved in and try and call the hands outloud.

It's all very read dependent though so keep that in mind. There are people that will play top pair with a 3 kicker like the absolute nuts. Generally speaking the really poor players are the hardest to put on a range of hands.