A line segment is a part of a line that is bounded by two distinct end points, and contains every point on the line between its endpoints.
A closed line segment includes both endpoints, whereas an open line segment excludes both endpoints; a half-open line segment includes exactly one of the endpoints.
A line segment can be constructed using a ruler only or with along with a compass.
If we want to draw a line of 4 cm, we can use a ruler and simple draw it by measuring 4cm.
Using a compass and ruler is another way of drawing a line segment.
Draw a line of any length and name it AB. Measure the compass for 4 cm and place the compass on point A and cut an arc on the line and name the point as C.