Hello,

Dravyaman :- kisi padarth/ vastu ka vo mul goon hai jo us padarth/ vastu ko gati mei jane se rokta hai. saral bhasha mei dravyman se hame kisi padarth/ vastu ke wajan ka pata chalta hai.

Mass :- Mass is the both property of physical body and measure of its resistance to acceleration when net force is applied. In simple words it is defined as object's mass also determines the Strength of its gravitational attraction to other bodies.

Good luck