An academic term is a division of an academic year, the time during which a school, college or university holds classes. These divisions may be called 'terms', 'semesters', 'quarters', or 'trimesters', depending on the institution and the country.
Institutions often have two semesters (four-month terms, though it literally means "six months") in an academic year, each lasting between 15 and 18 weeks. A quarter or trimester (three-month term) lasts between 8 and 12 weeks, and there are typically three per year. Other permutations are sometimes used – for example, two semesters each divided into two quarters, four quarters, or even three semesters.
In contrast to a calendar year, in most countries an academic year begins with the start of summer and ends the following spring. This is because it follows the medieval agricultural pattern of the year in northern Europe, in which July and August were when able-bodied young people were needed on the farms.