What is incarnation?

a person who embodies in the flesh a deity, spirit, or abstract quality.

Incarnation literally means embodied in flesh or taking on flesh. It refers to the conception and birth of a sentient being who is the material manifestation of an entity, god or force whose original nature is immaterial. In its religious context the word is used to mean the descent from Heaven of a god, or divine being in human/animal form on Earth.