What is difference between revaluation account and realization account?

Revaluation account and Realisation account both are nominal account.

the purpose of revaluation account is taking the effect of fluctuations in asset & liabilities in their books while purpose of realisation account is to closing the books of accounts of a comapany or a firm.

Revaluation a/c is made when any fluctuation in value of an asset takes place.

realisation a/c is made at the time of liquidation of a company or a firm.