Question

Differentiate b/w absolute refraction and refraction.

Answer 1

I don't think there is a concept like absolute refraction.If you want to difference absolute refractive index and relative refractive index ,it is as follows:

Absolute Refractive Index:The absolute refractive index (μ) of a medium is the ratio of the speed of light in vacuum (c) to the speed of light in that medium (v), i.e. μ = c/v.This is also known as refractive index of medium.

Relative Refractive Index:The refractive index of medium 2 with respect to medium 1 is the ratio of the speed of light in medium 1 to that in medium 2 i.e., μ₂₁ = v₁/v₂.This is the relative refractive index of medium 2 with respect to medium 1.
.I hope you know what refraction means,But anyway Refraction is the change in direction of wave propagation due to a change in its transmission medium.