Actually, it is a combination of the two, resulting in Power or Energy being absorbed by the body. This energy cause various problems for the human body, including:

• disrupting the operation of the nervous system and essential organs such as the brain and heart
• raising the temperature of critical organs - essentially cooking the body, normally after prolonged exposure or very large amounts of energy
• severe burns at the ingress and egress points, often multiple points especially in the case of lightning strikes.

Power/Energy varies as the square of both voltage and current.