A decomposition reaction is a type of chemical reaction where a single compound breaks down into two or more simpler substances. This process often requires energy in the form of heat, light, or electricity. For example, when water is subjected to electrolysis, it decomposes into hydrogen and oxygen gases. These reactions are important in various fields, including chemistry and environmental science. Decomposition reactions can occur naturally, such as the breakdown of organic matter by microorganisms, or can be induced in laboratories for research and industrial applications.