Campus (plural: campii) is Latin for "field" or "open space". English gets the words "camp" and "campus" from this origin.
The campus is the area in which a university and surrounding buildings are situated. Usually a campus includes libraries, lecture halls, student residential areas and park-like settings.
Sometimes the land on which company office buildings, with the buildings, are called campuses as well, e.g. the Microsoft Campus in Redmond, Washington, as are also hospitals with similar usage.
See also: Campus university