The process of determining the quantity of a substance A by adding measured increments of substance B, with which it reacts (almost always as a standardized solution called the @T06386@, but also by electrolytic generation, as in coulometric titration) with provision for some means of recognizing (indicating) the endpoint at which essentially all of A has reacted. If the endpoint coincides with the addition of the exact chemical equivalence, it is called the equivalence point or @S06021@ or theoretical endpoint, thus allowing the amount of A to be found from known amounts of B added up to this point, the reacting @W06668@ ratio of A to B being known from @S06026@ or otherwise. Terms for varieties of titration can reflect the nature of the reaction between A and B. Thus, there are acid–base, complexometric, chelatometric, @O04362@–reduction, and @P04795@ titrations. Additionally, the term can reflect the nature of the @T06386@, such as acidimetric, alkalimetric, and iodometric titrations as well as coulometric titrations, in which the @T06386@ is generated electrolytically rather than being added as a @S05924@.