Reference

In Taoism, "Shijie" refers to the liberation or deliverance from the physical body, which can be understood in several ways:

1. As a dissolution and transformation of the body.
2. As a release of the form and a fluxing transformation.
3. As shedding mortal forms and melting away.

There are many varieties of Shijie, including using a substitute corpse or employing supernatural techniques with alchemical swords to temporarily create a corpse. The process of death itself is described as Shijie or "release from the corpse," with what happens afterward being described as transformation, immortality, or ascension to heaven.

For more detailed information, you can refer to the Wikipedia page on Shijie (Taoism).