How does the splitting of spectral lines in the Zeeman Effect take place?

Hint :The Zeeman Effect is named after Dutch physicist Pieter Zeeman. The process of splitting of spectral lines into several components in the presence of a static magnetic field is known as Zeeman Effect. It just matches with the Stark effect. In the Stark effect the same process is done, only the difference is that it is done in the presence of an electric field.

Complete Step By Step Answer:
When the electron spins around the nucleus it generates a magnetic dipole moment. As the electrons are negatively charged, then the dipole moment which is being generated by them points perpendicular to the rear of the circumscribed by the spinning of the electron. The orbitals of an atom splits in the presence of an external magnetic field and how many splits have been done depends upon the orbital quantum number represented by l. Therefore, the number of splits $ = \left( {2l + 1} \right) $ . There is no splitting for the s orbital as we know the number of splits depends upon l and l for s is $ 0 $ . But, for p orbital the value of l is $ 1 $ , so the $ 2p $ orbital splits into $ 3 $ spectral lines $ \left( { = \left( {2l + 1} \right) = \left( {2 \times 1 + 1} \right) = \left( {2 + 1} \right) = 3} \right) $ . In this way we can say that Zeeman Effect describes the splitting of spectral lines in the presence of magnetic fields.

Note :
There is another form of Zeeman Effect which is none other than Inverse Zeeman Effect (when the spectral lines become absorption lines). There is also another Zeeman Effect which is the weak field Zeeman Effect (when spin orbit interaction dominates over the effect of the external magnetic field). It also has some important application in nuclear magnetic resonance spectroscopy and in many other fields.