What's the difference between Texas Hold'em and Poker?
Poker is a class of gambling card games, which you can play according to different rulesets. Texas Hold'em is one of those rulesets. In Texas Hold'em players are first dealt two secret cards each, followed by a betting round, then three open, public cards are dealt (the flop), with a subsequent betting round. The flop is followed by the turn, one more public card, and then a betting round. The turn is followed by the river, the final public card. A last betting round follows, and if more than one player is still in the hand at the end, the winner of that round is determined. 

The last player who bet on the river reveals his two secret cards, and makes the best poker hand out of the two secret cards and five public cards. Any other player who is still in the game may then reveal his two secret cards and make a better poker hand with the seven cards total if possible.