Description: Learn the difference between lines, line segments, and rays. Created by Sal Khan. What I want to do in this video is think about the difference between a line segment, a line, and a ray. But why we call it a segment is that it actually has a starting and a stopping point. So, most of the lines that we experience in our everyday reality are actually line segments when we think of it from a pure geometrical point of view.*Teacher Advisor is 100% free.