Poker is a card game that can be played by two or more players and involves betting. Each player places an ante (a small amount of money put into the pot) before being dealt cards. Then each player can decide whether to stay in the hand or fold. Players who do not fold and have the highest hand at the end of the hand win the pot.
Each player gets two cards that they can only see, called hole cards. There is then a round of betting, starting with the player to the left of the dealer. After this, 3 more cards are revealed, called the flop. There is another round of betting and then one more card is dealt face up, called the river. The final round of betting is again done by the player to the left of the dealer.
If you have a strong poker hand, bet it aggressively to force weaker hands out of the pot. You can also try to bluff in poker, and sometimes with good bluffing skills and luck you can make a bad hand into a winning one.
Generally speaking, you want to play only the best poker hands. This will help you maximize your winnings and minimize your losses. However, even pros will tell you that there are times to play a bad poker hand in order to get the pot moving. This is especially important in late positions where it is possible to manipulate the pot on later betting streets.