Question

define variation.what is it's importance

Answer 1

variation is the difference of genes between parent and their offsprings
it is very important for maintaining evolution. 

Answer 2

Variation means the differences amongst the individuals of the same species and the offspring of the same parents.
1.variations make some individuals better fitted in the struggle for existence.
2.they help the individuals to adapt themselves according to the changing environment.
3.they constitute the raw material for evolution.