Centre of Gravity, Centre of Mass, Centroid

CENTRE OF GRAVITY, CENTRE OF MASS, CENTROID

CENTRE OF GRAVITY
Centre of Gravity (CG) of a body is a point through which the resultant of distributed gravity forces act irrespective of orientation of body.

CENTRE OF MASS
It is the point where entire mass of a body may be supported to be concentrated.

CENTROID
Centroid is defined as geometrical centre of body.
In general when density of material is uniform through the body the positions of centroid and centre of mass are identical. If density varies these two points will not coincide.