The purpose of this review was to provide fundamental knowledge for the readers in the emerging field of polariton chemistry. Through the examination of the recent literature, this review aimed to provide, in a single location, much of the current working theoretical knowledge of polariton chemistry for the continued efforts of both the chemistry and quantum optics communities to actively participate in this exciting new research direction. Hopefully, this work can inspire the discovery of new principles and mechanisms of chemical reactions that take advantage of intrinsic quantum light-matter interactions and facilitate a quantum leap in chemistry. We envision that this review might lay the first several bricks toward facilitating a merge of quantum optics and chemistry. quantum mechanical behavior. His group is developing new quantum dynamics approaches that can accurately describe electron non-adiabatic transitions and nuclear quantum effects. Recently, his interest has been focused on Quantum Optics, Cavity Quantum Electrodynamics, and Polariton Chemistry.