What is the geometric term for a straight path that extends infinitely in one direction?

A ray is defined as a part of a line that begins at a specific point and extends infinitely in one direction. This means that it has a starting point but no end, allowing it to stretch out endlessly beyond that point. The geometric notation typically used for a ray includes an endpoint and an arrow indicating the direction in which it extends infinitely.

In contrasting terms, a line extends infinitely in both directions, while a line segment has two endpoints and does not extend beyond those points. A plane, on the other hand, is a flat, two-dimensional surface that extends infinitely in all directions within that dimension. Understanding these definitions clarifies why the term that defines a straight path extending infinitely in one direction is indeed a ray.