Question

What is crystallization? Where is it used? Why is this better than simple evaporation technique?

Answer 1

crystallization is the  process  of slow precipitation of solid crystal of a substance from concentrated homogeneous solution. It is used for the purification of solid substance. 
Crystallization technique is better than evaporation because 
1 Extent of purification in case of crystallization technique is very high
2 Does not require very high temperature condition, there is no need to boil the solvent.