What is the exact definition of legend and myth?

Answer 1

A legend is an unverifiable story handed down by tradition from earlier times and accepted as historical from traditions.

A myth is a story about superhuman begins of an earlier age taken by preliterate society to be a true account, usually of how natural phenomena, social customs, etc. came into existence.

Joseph Campbell defined myth as a story that may or may not be true itself, but is used to illustrate a truth of a given belief system.

Answer 2

A legend is a traditional story about the past that may or may not be based on real events or people, and often includes exaggerated or fantastical elements. A myth is a traditional story that explains the origins of the world, natural phenomena, or cultural customs, typically involving gods or supernatural beings.