In physics, "momentum" is a property that describes an object's motion. Linear momentum, the momentum of an object moving in a straight line, is the mass of the object multiplied by its velocity.
The term "momentum" is also used in a more abstract sense to indicate the driving force or impetus of a physical object, a set of circumstances or a course of events. For example, when sales of a particular product or commodity are picking up, one could say that the sales are gaining momentum. The term is also used to describe the success or failure of a career, a sports team, an economy or a military effort.