Pot is a casino term used in the game of poker, and it refers to the amount of money in the middle of the table.
Each time a player bets, raises, pays the antes, small blinds, or big blinds, all that money goes into the pot. Then, at the end of a hand, the winner receives all the money from the pot that has been accumulated throughout the hand. Naturally, with each new hand, the pot resets and the cycle starts anew.
One thing to note is that, while most of the time there is going to be only one winner who will receive all the money from the pot, that money can sometimes be split between two or even more players, depending on the variance of poker you are playing, house rules, and the strength of players’ hands.