"Straight" - A complete hand is dealt to each player, and players bet in one round, with raising and re-raising allowed. This is the oldest poker family; the root of the game as currently played was a game known as Primero, which evolved into the game Three-card brag, a very popular gentleman's game around the time of the American Revolutionary War and still enjoyed in the U.K. today. "Straight" hands of five cards are sometimes used as a final showdown, but poker is currently virtually always played in a more complex form to allow for additional strategy.
Stud - Cards are dealt in a prearranged combination of face-down and face-up rounds or "streets", with a round of betting following each. This is the next-oldest family; as poker progressed from three to five-card hands, they were often dealt one card at a time, either face-down or face-up, with a betting round between each. The most popular stud variant today, 7 card stud, deals two extra cards to each player (three facedown, four faceup) from which they must make the best possible 5-card hand. Draw - A complete hand is dealt to each player, face-down, and after betting, players are allowed to attempt to change their hand by discarding unwanted cards and being dealt new ones. 5 card draw is the most famous variation in this family.
Community - A variation of Stud, players are dealt an incomplete hand of face-down cards, and then a number of face-up "community" cards are dealt to the center of the table, each of which can be used by one or more of the players to make a 5-card hand. Texas hold-em and Omaha are two well-known variants of the Community family.
