Lifeform is the physical entity which encompasses a life. A lifeform is in a non-equilibrium thermodynamic state. A continuous energy input is required to maintain this state. Lifeforms expend a significant amount of time procuring and metabolizing food to obtain this energy. The human lifeform has made use of other forms of energy such as fire and tools which are used for the utilization of mechanical energy. This utilization of additional forms of energy has allowed humans to reduce the time required for subsistence, thus providing time for creative behavior.