Chemical kinetics is the branch of physical chemistry that studies the rates of chemical reactions and the factors that influence the speed at which reactions occur. It involves the study of the mechanisms of chemical reactions, the determination of reaction pathways, and the investigation of how various factors such as temperature, pressure, and concentration affect reaction rates. Chemical kinetics plays a crucial role in industries such as pharmaceuticals, material science, and environmental science, as it helps in optimizing reaction conditions and designing more efficient processes.