Definition:Endpoint


 * Endpoint (Geometry) the endpoint of a line segment.


 * Endpoint (Analysis) the endpoint of a real interval.

The concepts are related in the Real Number Line which is a one-to-one correspondence between a line and the set of real numbers.

An unrelated use of the term:


 * Graph Theory: The endvertices or endpoints of an edge $e$ are the vertices $u$ and $v$.