# Normal Vector

A normal vector is a vector perpendicular to a surface.

Normal vector is a high school-level concept that would be first encountered in a pre-calculus course covering vectors.

### Prerequisites

Perpendicular: | Two lines, vectors, planes, etc. that intersect at a right angle are said to be perpendicular. |

Plane: | A plane is a two-dimensional surface defined by linear equations. |

Vector: | (1) In vector algebra, a vector mathematical entity that has both magnitude (which can be zero) and direction. (2) In topology, a vector is an element of a vector space. |