Definition of Fixet Limit
When you play a poker variant that is "Fixet Limit" (fixed limit) it means that the limit for raises is set at all stages of a hand. When you play "Hold’em" no limit, at all stages of the hand, you can raise any amount you like. The only constraint is that you must have a stack big enough to raise. Basically, your mat constrains the size of your raises. When the variation is Fixet Limit, you will have to follow the rules of that variation to determine your maximum raises at each step of the hand.
Fixet Limit vs No Limit
Since 2003, Hold’em without limits has been the most popular form of poker. Before that time, in Las Vegas casinos, Hold’em Fixet Limit was very popular. It is less exciting than Hold’em No Limit, but the variance is less and the bluffs are less present. You will be able to play as many Hold’em's as Omaha's or Stud's in Fixet Limit's. Usually we will play at higher limits in Fixet Limit's. For example, a player with NL25 (blinds to 0.25/0.50) in Hold’em No Limit will be able to play with blinds to 1/2 in Hold’em Fixet Limit.