An "epoch" is a significant period in history or a person's life that is marked by notable events or changes. In geology, an epoch is a subdivision of a period in the geological time scale, which helps scientists understand the Earth's history and the evolution of life. For example, the Paleocene epoch followed the extinction of the dinosaurs and saw the rise of mammals. In computing, an epoch can refer to a specific point in time used as a reference for timekeeping. The most common example is the Unix epoch, which starts at January 1, 1970. This reference point allows computers to calculate and manage time efficiently.