''Life'' can be defined as the vital force which keeps an organism alive. The living state of a complex organic cellular substance capable of growth, reproduction and endowed with evolutionary potential forms life. Life is embodied within an organism and is inseparable from it. Hence, there is no life without a living body.

Metabolism refers to a two-fold process involving the breakdown and repair of the protoplasm called anabolism and catabolism. The constructive phase of protoplasm is called anabolism, and the destructive phase is called catabolism. Anabolism (repair phase) is the process where food materials are converted into more complex substances, and catabolism (waste phase) is the process where complex materials are degraded into simpler substances.

Living organisms have the ability to movement and locomotion. In other words, they have the power of automatic movement. This property of living beings is known as automatism. This process plays an essential role in the ability of living organisms.