The term "oxidative" refers to a process or substance that involves oxidation. Oxidation is a chemical reaction in which an atom, molecule, or ion loses one or more electrons and becomes negatively charged (a free radical). This can result in the formation of new compounds or materials with different properties than the original substance. In biological systems, oxidative stress occurs when there is an imbalance between the production of reactive oxygen species (ROS) and the ability of the body to detoxify them. Oxidative processes are involved in many natural phenomena such as rusting, aging, and cellular respiration, but they can also contribute to various diseases including cancer, heart disease, and neurodegenerative disorders.