Collinear means that three or more points lie on the same straight line. This property is called collinearity. In geometry, points are collinear if they exist on a single line, regardless of whether they are in the same plane or not. Two points are always collinear because a straight line can always be drawn through any two points

. The term comes from Latin, with "col-" meaning "together" and "linear" meaning "belonging to a line," literally meaning "lying on the same line"

. In summary:

• Collinear points: three or more points on one straight line.
• Two points are always collinear.
• Collinearity is the property of points lying on the same line