Moment means moment of inertia.. See.
For smaller objects we suppose them as a particle.But when it is a case of a body of a larger size we cannot make out the body as a particle. We have to calculate the moment of inertia of the object.
Here the large object's part are taken as
It is formula that moment of inertia of the mass is
The total moment of inertia of the object is
The moment of the object is written as