Poker is a card game in which players independently try to assemble the highest value hand of cards in order to win cash, chips, or other units. The game has many variants, but they all share the same essential elements: a dealer deals each player two cards face-down; players place an initial amount of money into the pot before they see their own cards; and betting rounds ensue where players can raise, call, or fold.
In between betting rounds the dealer puts three additional cards face up on the table that anyone can use; these are called the flop. After the flop is dealt there are another round of betting and then the fifth and final card, which is known as the river, is dealt face up. At this point the player with the best 5 card poker hand wins the pot with all of the bets made at each round.
If you have a strong draw you should be very aggressive with it and try to get your opponent to call your bets rather than play passively. This will help you win more hands.
While the short term luck element of poker is unavoidable it can be beaten with knowledge, practice, and patience. The mathematical concepts behind poker, such as frequency and EV estimation will become intuitive over time. These concepts are very important for becoming a profitable player.