A semester is a division of the academic year used by many educational institutions, such as colleges and universities. Typically, an academic year is divided into two main semesters: the fall semester and the spring semester. Each semester usually lasts around 15 to 18 weeks, during which students attend classes, complete assignments, and take exams. Some institutions also offer a summer semester, which is shorter and often more intensive. Semesters help organize the curriculum and allow students to focus on a specific set of courses during a defined period. This structure aids in planning and managing academic workloads effectively.