Myths and Legends are basically stories, and have existed for thousands of years probably longer. Ever since we have records man has told stories and some tend to elaborate the truth a little here and there; these stories we call myths and also legends, but what's the difference?
A legend first of all usually bears more truth than a myth. Legends are characterised as being based on truth and then adapted slightly as it is retold with slight additions through generations. Legends also usually bear some type of symbolic meaning for the people who told the original story. An example of a legend might be the Trojan War, it has symbolic meaning for the people of Dark Age Greece and the mystical bard Homer who is said to have first sung the Illiad and Odyssey (tales of the battle of Troy). However archaelogists have found limited findings regarding the tales and it seems that there may have been a battle for the island where Troy existed but was not necessarily as grand and heroic as the legendary tales make it out to be. Such heroes as Achilles and Ajax may have truly existed but their actions have been most likely far exaggerated. For example the shield that Achilles is said to weild would be too heavy for any man to hold and fight with and also his invulnerability barring his heel is impossible. Nevertheless legends are based on an original truth and then elaborated to become an epic tale, legendary in fact!
Myths are morality stories usually based on a legend or a tradition. They are not usually depicting a true event, their purpose is to provide a message through a story so in Pandora's box for example we learn to do as we are told by superiors and in Theseus and the Minotaur we are taught to be thankful and to repay kidness given to us or face consequences (some would say karma). This is not to say that Myths cannot be based on truth because they can but they are still usually elaborated greatly and altered in order to make for a better and more engrossing (captive) story. We still tell Myths that are thousands of years old because they teach us a lesson in morality and are exciting enough that we want to know the conclusions to the stories. The most popular are probably the Myths from Ancient Greece which the Romans took and altered to fit their Gods and a more Roman way of thinking, but they are similar still.
So just to conclude, legends are based on truth and bear a symbolic meaning for the people who originally created them whilst myths are usually fictional (not real) but bear a moral message within the story. Comment below with which you prefer! Also can you tell which of the articles in this section are myth and which are legend? Good luck!