Draw poker is any poker variant in which each player is dealt a complete hand before the first betting round, and then develops the hand for later rounds by replacing, or "drawing", cards.
A complete hand is dealt to each player, face-down, and after betting, players are allowed to attempt to change their hand (with the object of improving it) by discarding unwanted cards and being dealt new ones. Five-card draw is the most famous variation in this family.
Five-card draw (also known as a Cantrell draw) is a poker variant that is considered the simplest variant of poker, and is the basis for video poker. As a result, it is often the first variant learned by new players.
Source: Wikipedia, "[en.wikipedia.org]", available under the CC-BY-SA License.