If you are talking simply about the timing of reinforcement, there are two different types of schedule. One is called a fixed interval schedule and the other is called a variable interval schedule. There are also two other kinds of schedules. These are fixed ratio schedules and variable ratio schedules.
In fixed interval schedules, the reinforcement is given at a set time. For example, a rat could be reinforced once every minute. A variable interval schedul reinforces at random times.
A fixed ratio schedule reinforces a behavior every X number of times that it is done. For example, a rat might be reinforced every time it pushes a lever 10 times. For a variable ratio, the reinforcement is connected to the behavior, but it takes a more random number of behaviors to trigger the reinforcement.