Rake in poker is a fee/commission taken by a cardroom. This is how casinos and online poker rooms make money. 

Rake amount, specifically the rake cap, varies depending on the casino/online platform, stakes and number of players at the table. For example, in $2.5/$5 6max online games rake is around 4.5-5% of the pot in each poker hand, capped at $3-$8 (0.6-1.6bb) depending on the poker room. 

Some poker rooms rake preflop pots, others follow the “no flop, no drop” rule, which means the rake is only taken postflop.

There are also several non-percentage ways for a casino to rake the poker games, such as dead drop or time collection.

In dead drop the dealer, before dealing the cards, collects a fee from the player on the button. 

In time collection a set fee is collected every half-hour during the game. It can be done in two ways:

 - player time - a set amount is collected from each player
 - time pot - a set amount is taken from the pot every time it exceeds a certain value.

Rake has a significant influence on players’ strategy.