The definition of mythology is the telling of stories which usually contain legendary creatures, gods, or people. Mythology has been around for as long as people have. There is no one creator of mythology. Some famous mythical people and creatures include Hercules, Zeus, Unicorns, etc.
The definition of legends is a story that is passed down throughout the years. Legends have been around for as long as mythology has. Some examples of legends are Paul Bunyan, the Loch Ness Monster, Bigfoot, etc.