c-bets are generally used when you missed a flop, but feel you can push an opponent off and hand that beats you, but isn't great.

If you have 77, raise PF, flop is KQ2 rainbow, you can c-bet and maybe push him off a queen, JJ, 1010, 99, 88, weak king maybe.


But if you have QQ, and the flop is A72 rainbow, checking is better, there is no draws. If you bet out and are called, he likely has an A and you will have to go into check/fold mode unless you hit your Q on the turn. If he folds you probaly had the best hand. you gain nothing by betting out, and cound lure a possible bluff by checking. Maybe hope he catches some part of the turn and will pay you off more.