The Jade Emperor in Chinese folk culture, is the ruler of Heaven

Heaven

Heaven, the Heavens or Seven Heavens, is a common religious cosmological or metaphysical term for the physical or transcendent place from which heavenly beings originate, are enthroned or inhabit...

 and all realms of existence below including that of Man

Man

The term man is used for an adult human male . However, man is sometimes used to refer to humanity as a whole...

 and Hell

Hell

In many religious traditions, a hell is a place of suffering and punishment in the afterlife. Religions with a linear divine history often depict hells as endless. Religions with a cyclic history often depict a hell as an intermediary period between incarnations...

, according to a version of Taoist mythology

Chinese mythology

Chinese mythology is a collection of cultural history, folktales, and religions that have been passed down in oral or written tradition. These include creation myths and legends and myths concerning the founding of Chinese culture and the Chinese state...

. He is one of the most important gods of the Chinese traditional religion pantheon

Pantheon (gods)

A pantheon is a set of all the gods of a particular polytheistic religion or mythology.Max Weber's 1922 opus, Economy and Society discusses the link between a...

. In actual Taoism, the Jade Emperor governs all of the mortals' realm and below, but ranks below the Three Pure Ones

Three Pure Ones

The Three Pure Ones also translated as the Three Pure Pellucid Ones, the Three Pristine Ones, the Three Divine Teachers, the Three Clarities, or the Three Purities is the Taoist Trinity, the three highest Gods in the Taoist pantheon. They are regarded as pure manifestation of the Tao and the...

.

The Jade Emperor is known by many names, including Heavenly Grandfather (天公 Tiān Gōng) which is used by commoners; the Pure August Jade Emperor, August Personage of Jade (玉皇上帝 Yu Huang Shangdi or 玉皇大帝 Yu Huang Dadi); the Xuanling High Sovereign; and his rarely used, formal title, Peace Absolving, Central August Spirit Exalted, Ancient Buddha, Most Pious and Honorable, His Highness the Jade-Emperor, Xuanling High Sovereign (太平普度皇靈中天至聖仁義古佛玉皇大天尊).
There are many stories in Chinese mythology

Chinese mythology

Chinese mythology is a collection of cultural history, folktales, and religions that have been passed down in oral or written tradition. These include creation myths and legends and myths concerning the founding of Chinese culture and the Chinese state...

 involving the Jade Emperor.
It was said that the Jade Emperor was originally the crown prince of the kingdom of Pure Felicity and Majestic Heavenly Lights and Ornaments.