A star's gravitational contraction is the inward force of gravity that pulls all of the star's matter inward. This force is opposed by the star's own internal pressure, which is generated by the star's heat and nuclear reactions.

Neutron degeneracy pressure is a type of pressure that is generated by the neutrons in a star's core. This pressure opposes the star's gravitational contraction, preventing it from collapsing in on itself.
Chandrasekhar limit refers to the greatest amount of mass that a white dwarf can have before collapsing under the influence of its own gravitational pull.

Essentially, the Oppenheimer-Volkoff limit is the greatest mass that a neutron star can have before collapsing under the gravitational pull of its own gravity.

If a star's gravitational contraction is balanced by neutron degeneracy pressure, its mass will be between the Chandrasekhar and Oppenheimer-Volkoff limits. Both of these limits are related to the amount of pressure that can be generated by the neutrons in a star's core. As the mass of a star increases, the force of its gravitational contraction will increase, eventually overcoming the force of neutron degeneracy pressure. This will cause the star to collapse in on itself, forming a black hole.

Step-by-step explanation

Reference

Rajesh, T. (2017). Existence of Black Neutron Star. International Journal of Astronomy and Astrophysics, 5(01), 11.

Panah, B. E., & Liu, H. L. (2019). White dwarfs in de Rham-Gabadadze-Tolley like massive gravity. Physical Review D, 99(10), 104074.