"A body or collection of myths belonging to a people and addressing their origin, history, deities, ancestors, and heroes." and another definition ; "A body of myths; esp., the collective myths which describe the gods of a heathen people; as, the mythology of the Greeks."
Mythology is an organized collection of myths, or stories,that more often than not explains our history. Myths usually confront major issues such as the origin of humans and how the natural and man-made. However, there are also myths that tell you the day-to-day lives and important events in the lives of the deities, such as their love affairs, pleasures and jealousy.
What is the difference between a myth and a legend?
Sometimes, myths also explain our deaths, or rather, our fates after death. They also encourage an aura of mystery in that sense, for example, they might say that a flood is a sad diety and a drought an angry one.