Euler angles used to represent orientation with 3 angles in a 3D space.
Euler angles of a 3D orientation is a combined rotation of 3 angles. Those angles marked α, β, γ. There are two types of convention, x-convention and y-convention. In case of x-convention,
- α is the rotation about the unmodified
Zaxis - β is the rotation about the modified
Xaxis - γ is the rotation about the modified
Zaxis
This is called z-x'-z" sequence.
See also Wikipedia.