There are two major differences between "center of gravity" and "center of mass":

1) The term "center of gravity" aplies to the bodies with mass and weight, while the term "centroid" applies to plan areas.
2) Center of gravity of a body is the point through which the resultant gravitational force (weight) of the body acts for any orientation of the body while centroid is the point in a plane area such that the moment of the area, about any axis, through that point is zero.
Center of gravity is the point at which a object can be suspended and be in perfect equilibrium