: Not to be confused with Dimension of a physical quantity. For other uses, see Dimension (disambiguation).
In physics and mathematics, the dimension of a space or Mathematical object|object is informally defined as the minimum number of coordinates needed to specify any point (geometry)|point within it. Thus a line (geometry)|line has a dimension of one because only one coordinate is needed to specify a point on it (for example, the point at 5 on a number line). A surface such as a plane (mathematics)|plane or the surface of a Cylinder (geometry)|cylinder or sphere has a dimension of two because two coordinates are needed to specify a point on it (for example, to locate a point on the surface of a sphere you need both its latitude and its longitude). The inside of a cube, a cylinder or a sphere is three-dimensional because three co-ordinates are needed to locate a point within these spaces.
In physical terms, dimension refers to the constituent structure of all space (cf. volume) and its position in time (perceived as a scalar dimension along the t-axis), as well as the spatial constitution of objects within—structures that correlate with both wave-particle duality|particle and field conceptions, interact according to relative properties of mass—and are fundamentally mathematical in description. These, or other axes, may be referenced to uniquely identify a point or structure in its attitude and relationship to other objects and occurrences. Physical theories that incorporate time, such as general relativity, are said to work in 4-dimensional spacetime, (defined as a Minkowski space). Modern theories tend to be higher-dimensional including Quantum field theory|quantum field and string theory|string theories. The state-space of quantum mechanics is an infinite-dimensional function space.
The concept of dimension is not restricted to physical objects. High-dimensional spaces occur in mathematics and the sciences for many reasons, frequently as configuration spaces such as in Lagrangian mechanics|Lagrangian or Hamiltonian mechanics; these are abstract spaces, independent of the physical space we live in.

: Not to be confused with Dimension of a physical quantity. For other uses, see Dimension (disambiguation).
In physics and mathematics, the dimension of a space or Mathematical object|object is informally defined as the minimum number of coordinates needed to specify any point (geometry)|point within it. Thus a line (geometry)|line has a dimension of one because only one coordinate is needed to specify a point on it (for example, the point at 5 on a number line). A surface such as a plane (mathematics)|plane or the surface of a Cylinder (geometry)|cylinder or sphere has a dimension of two because two coordinates are needed to specify a point on it (for example, to locate a point on the surface of a sphere you need both its latitude and its longitude). The inside of a cube, a cylinder or a sphere is three-dimensional because three co-ordinates are needed to locate a point within these spaces.
In physical terms, dimension refers to the constituent structure of all space (cf. volume) and...