Poker is a game in which players bet and then reveal their cards to make the best five-card hand possible. There are many variations on the core game but all have a few common threads. Players can win by betting that they have a better hand than the others or by bluffing to make other players call their bets and concede.
Players start by putting chips into the pot (representing money) at the beginning of each betting interval (as determined by the rules of the specific poker variant). The player to the left of the dealer is then granted the privilege or obligation to make the first bet. Then the player to his or her right may raise that bet and so on.
Then the dealer puts three cards on the table that anyone can use (called the flop). Again, everyone gets a chance to bet/check/raise/fold. Finally, the dealer puts a fifth card on the board that everyone can use – this is called the river. After all of these cards are revealed the player with the highest ranked poker hand wins the pot.
As you play more and more poker, the math concepts like frequencies and EV estimation will become more and more ingrained in your brain. You’ll begin to have a natural intuition for these things and your poker game will improve quickly.