Peroxidase is an enzyme found in plants and animals that catalyzes the decomposition of hydrogen peroxide into water and oxygen. There are several synonyms for the word peroxidase, such as oxidoreductase, hydrogen peroxide oxidoreductase, and peroxidatic enzyme. In addition, there are specific types of peroxidases that are named based on the substrate they act upon, such as lignin peroxidase, horseradish peroxidase, and manganese peroxidase. These enzymes have important roles in various biological processes, such as plant growth, immune response, and detoxification. The identification and study of peroxidases have significant applications in medicine, environmental remediation, and biotechnology.