# Plane (mathematics)

In mathematics, a **plane** is a two-dimensional space or flat surface that extends indefinitely.
A plane is the two-dimensional analogue of a point (zero dimensions), a line (one dimension) and three-dimensional space.

This article's lead section may be too short to adequately summarize the key points. (February 2023) |

When working exclusively in two-dimensional Euclidean space, the definite article is used, so *the* Euclidean plane refers to the whole space.

Many fundamental tasks in mathematics, geometry, trigonometry, graph theory, and graphing are performed in a two-dimensional or *planar* space.[1]