Probability theory is a branch of mathematics that deals with the analysis of random events. It provides a framework for quantifying uncertainty, allowing us to calculate the likelihood of various outcomes. For example, when flipping a coin, probability theory helps us understand that there is a 50% chance of landing on heads and a 50% chance of landing on tails. This theory is widely used in various fields, including statistics, finance, and science. It helps in making informed decisions based on the likelihood of different scenarios. By applying probability, we can better understand risks and make predictions about future events.