Call is a poker term that refers to the player accepting the current wager set by a previous player or the player before him before passing the action to the next player sitting clockwise of him.
When you’re playing poker, there are several actions available to you during a hand, such as check, raise, all-in, fold, as well as call. If a player on your right raises $50, that means in order for you to continue playing and stay in the round, you need to either call their $50 or raise.
In many casinos, especially if you are playing online, you can call in advance, which can be very useful if you like playing fast. However, keep in mind that the decision is often irreversible. Therefore, you should do this only when you are confident enough that you have a strong hand.