Illustrated about the term bending moment?

Bending Moment

The critical section for bending moment for masonry or concrete block walls is half-way between the centre line and edge of the wall. For gusseted bases the critical section is half-way between the face of the column and edge of the gusseted base.
IS specifies that the critical section for reinforced concrete footings supporting reinforced concrete columns is at the face of the column as in below demonstrated figure:

Footing Moment Analysis