Bluff
A bet made to make better hands fold.
The button opens 8h 7h; the big blind defends with 6c 6d. The flop comes Kd 9s 4c. The button has 8-high with no pair and no draw. The big blind has a pair, but sixes can't beat a king. The button fires half the pot and the big blind folds the better hand. That's the whole idea: a bet with no showdown value wins the pot because a stronger holding gives it up.
It doesn't have to work every time. Fire half the pot and you need the fold only a third of the time to profit — you're risking half a unit to win the unit already sitting there. That's why bluffing pays even if you never plan to get caught. It turns dead hands into winners, and it forces folds that get your value hands paid, since no one can fold to every bet you make.
The common mistake is firing without asking who's left and what they hold. A bluff into three players needs all three to fold, and that gets unlikely fast. A bluff into a station who never lays down a pair just burns chips. Your bet has to tell a story that fits the board and the player, not just look scary.