Distinguish betwe

We know light is an electromagnetic wave whose direction of propagation is perpendicular to magnetic field and electric field and they both are also mutually perpendicular.

So, a light wave may have direction of its electric field and magnetic field changing i.e. they are vibrating in more than one direction.

This is because the source of the electromagnetic wave that is vibrating charges, which is vibrating in a variety of directions hence their electric field and magnetic field is regularly and alternately changing.

And almost all the light sources generate unpolarised light in which electric and magnetic fields vibrates in almost all directions.

And when the direction of vibration of electric field and magnetic field are restricted to one plane then it is called plane polarised light.

And the process of converting unpolarised light into a polarised light is known as polarization.

Which can be achieved through various methods

Polarization by reflection

Polarization by refraction

Polarization by scattering