In everyday talk we tend to interchange the terms mass and weight which makes most people believe that they mean the same thing.
Physicists have distinct meanings for the two.
Mass can be described in two ways. It is an objects tendency to resist motion, or inertial mass. Something more massive tends to resist motion more than something less massive. Mass can also be described by its gravitational attraction to another mass. Weight is the measurment of the force of gravity on a mass.