What is a ray in geometry?

Ray is the collection of points extended infinitely in one direction.  

Answer: In geometry, a ray is a line with one end or origin point and it extends infinitely in the other direction.

Let us understand the concept with an image.

Explanation:

Look at the ray PQ shown below.

In ray PQ, P is the endpoint and it can be extended infinitely in the direction of point Q.

Hence, in geometry, a ray is a straight line with one end or origin point and it extends infinitely in the other direction.