Double displacement, also known as double replacement, is a type of chemical reaction where two compounds exchange ions or elements to form two new compounds. This reaction typically occurs in aqueous solutions and involves the formation of a precipitate, gas, or water as one of the products. In a double displacement reaction, the general formula can be represented as AB + CD → AD + CB, where A and C are cations, and B and D are anions. Common examples include the reaction between sodium chloride and silver nitrate, resulting in the formation of silver chloride and sodium nitrate.