Sense and reference
In the philosophy of language, the distinction between sense and reference was an idea of the German philosopher and mathematician Gottlob Frege in 1892 (in his paper "On Sense and Reference"; German: "Über Sinn und Bedeutung"), reflecting the two ways he believed a singular term may have meaning. The reference (or "referent"; Bedeutung) of a proper name is the object it means or indicates (bedeuten), whereas its sense (Sinn) is what the name expresses.