The ego is a center in the mind, it is for self-consciousness and self-identification program that separates human personality from his/her own perfect spirit (divine self, Atman). By ego we mean the whole personality itself, since the personality is created by the ego center. Accordingly, the ego has layers.
We can identify ourselves with our physical body (material self-consciousness; I am this material body), our etheric body (subtle material self-consciousness; I am the life energy field that permeates my body), our astral body (the whole emotional world that makes up our personality; I am a good-humored, polite, friendly person), our mental body (the whole thought world that makes up our personality ...