What beats what?

From weakest to strongest: high card, one pair, two pair, three of a kind, straight, flush, full house, four of a kind, straight flush.

A royal flush is the ace-high straight flush. A straight is five consecutive ranks; a flush is five cards of one suit. A full house combines three cards of one rank with two of another.

An ace can end a high straight (T-J-Q-K-A) or start a low straight (A-2-3-4-5). It cannot wrap around through K-A-2.