John 19:30 Jesus gave up the ghost

³⁰  ...Jesus... said, It is finished: and he bowed his head, and gave up the ghost. -John 19:30 Bible, King James Version

A ghost is another name for a spirit. There are the spirits of mankind who have a physical body and those who do not. When Jesus gave up the ghost this simply means He discarded His outer body and continued to live as a spirit in the Spirit World.