A line is a group of points on a straight path that extends to infinity.
Any two points on the line can be used to name it. This line is called line DE.
A line segment is a part of a line that has two end points.
The two end points of the line segment are used to name the line segment. This line segment is called segment XY.
Using the graphic to the left: Name a line: Name a line segment with U as an end point: Name a ray with V as an end point: