A rotation is a circular movement of an object around a center (or point) of rotation. On a mobile device, it indicates the change of orientation.
A three-dimensional object rotates always around an imaginary line called a rotation axis. If the axis is within the body, and passes through its center of mass the body is said to rotate upon itself, or spin. A rotation about an external point, e.g. the Earth about the Sun, is called a revolution or orbital revolution, typically when it is produced by gravity.
Mathematically, a rotation is a rigid body movement which, unlike a translation, keeps a point fixed. This definition applies to rotations within both two and three dimensions (in a plane and in space, respectively.)
A rotation is commonly represented using euler-angles, a rotation matrix or quaternions.
On a mobile device, it indicates the change of orientation.
