What was the Egyptian concept of a person's life force?

The story behind the answer

Ka is the ancient Egyptian concept of a person’s life force—the vital energy that animates the body. Egyptians believed the ka was born with you, looked like your spiritual “double,” and needed nourishment after death. That’s why tombs included food, drink, and “ka-statues,” and why false doors were carved so the ka could receive offerings.

To distinguish the terms: the Ba is the personality that could move between the worlds (often shown as a bird with a human head); the Akhu (Akh) is the “effective” transfigured spirit achieved after proper rites;