center

Center is a term used to denote a point, place, or object that is in the middle or serves as a hub for activity. It can describe a precise mathematical point, a geographic or organizational focal point, or a facility that concentrates services or activities.

In geometry, the center of a circle is the point equidistant from all points on the circle. For polygons and more complex figures, several centers are defined, including the centroid (balance point), the circumcenter (intersection of perpendicular bisectors), and the incenter (center of the inscribed circle). The center of mass is the point at which an object's mass can be considered to be concentrated; in statics and dynamics this helps simplify calculations. In statistics, the term center often refers to a measure of central tendency, such as the mean, median, or mode, describing where values tend to cluster.

A center is also a place or organization: a community center, cultural center, research center, or data center. These facilities host services, workplaces, or activities and often serve as a local or institutional hub. The word can also describe the act of moving something toward the middle, as in to center a cursor or to center a plot.

The American spelling is center, while centre is the preferred form in British English and many other varieties. Related terms include center point, central, and centroid.