re: Poker & 3 betting and fold equity
3bet - a re-raise. For example, you hold QQ on the button, UTG raises to 4x the big blind, everyone folds to you, you now can re-raise UTG, which is a 3bet (if UTG re-raises you, it's a 4bet). This generally indicates that you have a very good hand, which provides you with:
Fold equity - there are two ways to win a hand, by having the best hand at showdown or by having everyone else fold before showdown. Representing strength is a way to get everyone else to fold. And, whether you win at showdown or before showdown, the fruit of your labor is:
Shipping - winning the pot.