Why is the statement “Everest is Chomolungma” informative according to Frege’s theory of meaning?

According to the theory of meaning developed by the German philosopher and mathematician Gottlob Frege, the statement “Everest is Chomolungma” is informative because it demonstrates his distinction between an expression’s referent (Bedeutung) and its sense (Sinn).1

While both “Everest” and “Chomolungma” share the same referent—the mountain itself—they possess different senses, which Frege defined as the “mode of presentation” of that referent. Because these names present the mountain in different ways, they make distinct contributions to the thought expressed by the sentence.1

This explains why the identity statement “Everest is Chomolungma” can represent a genuine geographic discovery, whereas the trivial statement “Everest is Everest” does not. In the latter case, the sense is identical on both sides of the identity, providing no new information. By separating the object referred to from the way that object is presented, Frege provided a logical framework to account for how such identity statements can be cognitively significant.12