A plane is a flat surface that extends infinitely in all directions. Given any three non-collinear points, there is exactly one plane through them.
A plane can be named by a capital letter, often written in script, or by the letters naming three non-collinear points in the plane.
For example, the plane in the diagram below could be named either plane or plane .
Two planes can be parallel (planes and in the figure below), or they can intersect in a line (planes and .)