  The study of particle creation phenomena at the expense of the gravitational
field is of great research interest. It might solve the cosmological puzzle
single-handedly, without the need for either dark energy or the modified theory
of gravity. In the early universe, following graceful exit from inflationary
phase, it serves the purpose of reheating the cold universe, which gave way to
the hot Big-Bang model. In the late universe, it led to late time cosmic
acceleration, without affecting stand-ard Big-Bang-Nucleosynthesis (BBN),
Cosmic Microwave Background Radiation (CMBR), or Structure Formation. In this
chapter, we briefly review the present status of cosmic evolution, develop the
thermodynamics for irreversible particle creation phenomena and study its
consequences at the early as well as in the late universe.
