Mythology refers either to the study of myth or is used to refer to a collection of myths from a particular culture or society. The word myth comes from the Greek word mythos, which means story or word. Myths are narratives that were created by ancient people to explain aspects of the world that they did not understand. Natural and supernatural phenomena, creation of the universe, and the origin of human practices or institutions are all subjects that mythology attempts to explain. Usually, the unexplained phenomena are attributed to the actions of deities or other supernatural figures.
Creation stories are a type of mythology that attempt to explain the existence of the universe. These narratives appear in almost every known society and involve the actions of a god or group of gods who made the Earth and its people. In Christianity, for example, the book of Genesis in the Bible tells the story of how God created the Earth and then made the first man and woman to populate it. In ancient Egypt, the Earth was created by the continual flooding of a body of water called Nu, which represented chaos and absence of life or order. Creation mythology among Aboriginal peoples in Australia tells the story of a rainbow snake who gave birth to the Earth as well as its first animal and human inhabitants.
Ancient societies created mythology to explain other aspects of their world as well, such as natural phenomena. The Greeks believed that the sun’s path across the sky was the god Apollo, also called the sun god, driving his chariot. Similarly, natural disasters such as earthquakes and stormy seas were said to be caused by Poseidon, the Greek god of the ocean, striking the ground with his trident. In Norse mythology it was Thor, the god of thunder, whose anger caused natural disasters and destruction. In New Zealand, the Maori attributed the existence of morning dew to the tears of Rangi, the god of heaven who was separated from his wife Papa, the goddess of Earth.
Many human institutions, rituals, and holidays also have roots in mythology. The English names for the days of the week as well as the planets in the solar system came from the names of ancient gods and goddesses. Halloween, which is now a popular holiday for children to dress up and go trick-or-treating, began as a Celtic festival called Samhain, during which the boundaries between the human and spiritual worlds were loosened and normal rules of conduct did not apply.