A probability model is a model used to represent a random situation or an experiment. A probability model is defined by a sample space, the events and outcomes that make that sample space, and the probability of each of these events. Depending on the situation, one probability model may suit the situation better than others. The table below shows two of the most commonly used models.

Probability Model	Description
Uniform Probability Model	Every outcome has the same probability.
Geometric Model	Each outcome has an associated region in a geometric shape.