f(R) gravity and its astrophysical significance

f(R) theories of gravity are a class of the family of extended theories of gravity formed by perturbing the approach to general relativity. Such theories help us in understanding several important features in astrophysics, such as accelerated expansion of the universe or the dynamics of cosmologies. In this talk, I will briefly discuss several important points, starting from formalisms towards deriving the field equations in such theories, and aiming at understanding the implications of different f(R) theories.