What's the difference between theoretical probability and experimental probability

Theoretical probability is the likelihood of a certain event occurring calculated based on all the possible outcomes. (Theorizing about the probability of a certain occurrence)

Experimental probability is the likelihood of a certain event occurring calculated by performing trials of an activity and recording the number of times an event occurs, then dividing the total number of even occurrences by total number of trials. (Experimenting to find probability of a certain occurrence)