Probability theory is a branch of mathematics that deals with the analysis of random phenomena and uncertainty. It provides a framework for quantifying the likelihood of different outcomes in various situations. Central concepts in probability theory include experiments, outcomes, events, and probabilities. An experiment is a procedure that yields one of several possible outcomes, while an outcome is a possible result of this procedure. An event is a set of outcomes, and the probability of an event is a measure of how likely it is to occur. Probability theory is fundamental in fields such as statistics, finance, science, and engineering, where it helps in making informed decisions based on the analysis of random processes and data.