Definition
Endpoint
An endpoint is a point that marks an end or boundary of a segment, ray, interval, or path.
Continue from this idea into connected AXIO math.
What it means
A segment stops at both endpoints. A ray begins at its endpoint and continues forever in one direction. On a number line, an interval’s endpoint is a boundary value; a filled or open mark tells whether that value belongs to the interval.
Remember it
A segment stops at two endpoints; a ray starts at one.
Example
Segment AB has endpoints A and B. Ray AB has endpoint A, passes through B, and keeps going beyond B, so B is not its endpoint.
Watch for
A point in the middle of a segment is not an endpoint, and a full line has no endpoints because it continues both ways.
Common mix-up
For a ray, the endpoint is its starting point, not an arrowhead showing that the ray continues.
Exact meaning
An endpoint is a point marking an end or boundary of a mathematical object. A line segment has two endpoints, a ray has one endpoint, and a line has none. An interval has endpoint values whether those values are included or excluded.