Semantics

In semantics, reference is generally construed as the relation between nouns or pronouns and objects that are named by them. Hence the word "John" refers to John; the word "it" refers to some previously specified object. The objects referred to are called the "referents" of the word. Sometimes the word-object relation is called "denotation" for clarity.

Reference is not in general the same as meaning, as words can often be meaningful without having a referent. Fictional and mythological names such as "Bo-Peep" and "Hercules" show that this is possible. As Frege discovered, reference cannot be treated as identical with meaning: "Hesperos" (an ancient Greek name for the evening star) and "Phosphorus" (an ancient Greek name for the morning star) both refer to Venus, but the astronomical fact that '"Hesperos" is "Phosphorus"' can still be informative, even if the 'meanings' of both "Hesperos" and "Phosphorus" are already known. This problem led Frege to distinguish between the sense of a word and its reference.