Turn
The fourth community card. Bets usually grow here; draws get expensive.
You're on the button with Kd Jd. UTG opens, you call, and the flop comes Qd 8d 3c. The pot is 30 before UTG bets 20. Calling creates 70 total, a 28.6% price, while nine diamonds are only about 19% to arrive on the next card. The flop call is not directly priced in; it works only if position and the roughly 35–40 extra chips you expect to win on a diamond supply enough implied odds. The turn is the 2s, a blank, and UTG fires again.
That is the turn's trap: the draw has one chance left and future payoff is shrinking. Nine outs with both cards guaranteed are about 35% to fill the flush. With only the river left, that drops to roughly 19%, about 4-to-1 against. Recalculate using the new pot and bet instead of carrying the flop's by-river number forward.
Beginners treat the turn like an extension of the flop and call from habit. Good players re-check on every street: pot before the new bet, price after their call, next-card equity, and realistic implied odds if the draw hits. If those no longer cover the gap, fold.