What it the Zeeman effect and what does it tell us about the Sun?

Zeeman Effect -

In the presence of static magnetic field, the process of splitting of the spectral line into several components, is called Zeeman effect.

On the sun, there is a strong magnetic field, and hence, can show Zeeman effect.

And due to this,

The sunspots can be studied by using this effect.

Sunspots are the darker region on the surface of Sun.