The pot in poker refers to the sum of money that players wager during a single hand or game, according to the betting rules of the variant of Poker being played.
Main Pot: Contains all chips bet of all player are placed in Main Pot.
Side Pot: Created once a player is all in and other players continue betting "on the side" (literally). The side pot is distinct from the main pot in that only the players still betting play for it, while the all-in player can only win the main pot. If there are multiple all-in players, multiple side pots can potentially be created. (Side Pot 1, Side Pot 2…)
Active Pot: contains the bet amount belongs to the current bet. (That could be the main pot or the side pot, if that pot is still being bet).
Pot Limit Omaha: utilizes the pot bet system, which means that you can bet up to the size of the pot. So, if the size of the pot is $100, your maximum bet size would be $100, assuming that nobody has yet to act in the hand. If the size of the pot is $100 and somebody puts out a $50 bet, then your maximum bet size would be $150, as pot bets include the money that is in the pot (100$), plus the $50 bet from your opponent.
The players who take part in each Pot, will compare poker hand against each other to choose the winner and win a prize from that Pot.
Rake: Chips taken from the pot by the Cardroom for compensation for hosting the game. (Ace Poker will take 5% Chip from each Pot).