There are three different betting structures in poker tournament. Using these betting structures the player plays the poker in different variants. The available betting structures are Limit, No-Limit, Pot-Limit.
In limit structured game, the only valid bet or raise is the current limit. For example 5$ is the bet in the first two rounds in a 5$-10$ Holdem game. There can be a max of four bet raises in betting round. This include bet, re-raise, cap, and raise.
In no-limit structured game, the bet raise must be atleast higher than the current limit or the last bet. Higher limit is not available. There is no limit for number of raises.
In pot-limit, the bet raise must be higher than the current limit. A pot limit bet or raise can be the highest to the value of pot and all the bets at table. There is no limit for number of raises.