Theoretical probability is the term used to describe what we expect to happen based on math theory, whereas experimental probability refers to what actually happens when the actual situation is tried out as an experiment.
We can relate the two types of probability by comparing their values - the values should be relatively close. In most experiments, they will not be equal, but they should be relatively close; if not, it may be that the experiment was conducted improperly or more trials need to be completed.
