The Euler angles are three angles introduced by Leonhard Euler to describe the 3D orientation of a rigid body.
The idea of Euler angles is to split the complete rotation of a cartesian coordinate system into three simpler rotations about the axes of this system. Euler angles also represent three composed rotations that move a reference frame to a given referred frame. This is equivalent to saying that any orientation can be achieved by composing three elemental rotations (rotations around a single axis), and also equivalent to saying that any rotation matrix can be decomposed as a product of three elemental rotation matrices.
