A flush is any five cards of the same suit. A straight is any five cards of more than one suit in sequence. Three of a kind is any three cards of the same denomination, plus any other un-matching cards. Two pairs is any two cards of the same denomination, plus two cards of another denomination, plus any fifth card. One pair is any two cards of the same denomination, plus any three other cards.
Some authorities trace poker to the Persian game as nas.
Brelan evolved into bouillotte, which flourished during the French Revolution. It is from this game that the betting techniques of poker are derived. Brelan also gave rise to ambigu, which included the draw feature, and the English game of brag, which incorporated bluffing.