Full explanation — Set
A set is a very strong three-of-a-kind hand, consisting of a pocket pair in your hole cards and one matching card on the community board. Sets are exceptionally valuable in poker because they are completely disguised, making them difficult for opponents to put you on. This deception allows you to extract significant value from unsuspecting opponents who often continue with lesser hands. While hitting a set on the flop only happens about 11.8% of the time with a pocket pair, the implied odds often make calling raises with pairs highly profitable.