Geometric probability is a branch of probability that uses geometric measures, such as length, area, and volume, to determine the likelihood of an event occurring. It often involves scenarios where outcomes are represented in a geometric space, allowing for the calculation of probabilities based on the relative sizes of different regions. For example, if you want to find the probability of randomly landing a dart on a specific area of a dartboard, you would compare the area of that section to the total area of the board. This approach can also be applied to problems involving lines, shapes, and random points in geometry.