End point - points on either end of a line segment or on one end of a ray.
Ray - A part of a line, with one endpoint, that continues without end in one direction
Line - a line of points that extends infinitely in two directions
Collinear - points that lie on the same line
Midpoint - A point that divides a segment into two congruent segments
Plane - A flat surface on which a straight line joining any two points would wholly lie.
3 dimensions - height, width, and depth