Mass percent :- In chemistry, concentration or mass percent is the measure of how much of a given substance there is a  mixed with another substance . This can apply to any sort of chemical mixture, but most frequently is used in relation to solutions, where it refers to the amount of solute dissolved in solvent.
Volume percent:- It is a common expression of a solution's concentration. It is the volume fraction expressed with a denominator of 100, and thus is defined as: 

volume percent volume of solute/ volume of solution * 100
volume percent is usually used when the solution is made by mixing two fluids , such as gases or liquids. however, percentages are only additive for ideal gases.