The four quantum numbers describe different aspects of an electron in an atom:

1. Principal quantum number (n): Determines the main energy level and the size of the orbital.
2. Azimuthal quantum number (l): Determines the shape of the orbital (e.g., spherical for s, dumbbell for p).
3. Magnetic quantum number (mₗ): Determines the spatial orientation of the orbital relative to a standard set of coordinate axes. For a given subshell l, there are (2l + 1) possible values of mₗ, corresponding to the different orientations (e.g., p_x, p_y, p_z or the d-orbitals d_{xy}, d_{z^2} discussed in Crystal Field Theory ).
4. Spin quantum number (mₛ): Describes the spin orientation of the electron itself.