What are the benefits from using stirrups in reinforced columns?

stirrups is like using belt to vanish the bulking force and shear force

Dear Mohamed Rabie, Your answer looks very good. In addition to the buckling and shearing forces, the stirrups must also bear the horizontal splitting tensile forces. For example, this is the case when there is a change in the cross-section or when concentrated loads are acting at a partial area on the upper or lower side of the pillars.

shear force to be held and resist