Environment
In the ambit of biology and ecology, the term environment indicates everything with a living being comes into contact, influencing its life cycle.
Biodiversity
The term biodiversity means the great variety of forms through which the phenomenon of life, in all its levels of organization, manifests itself on the planet earth.
Ecosystem
An ecosystem is a defined systemic whole (often called an "ecological unit") made up of living organisms (animal and plant species) that interact with each other and with the environment around them. As such it is a portion of the ecosphere and therefore of the biosphere.
Living organism
A living organism, in biology, is an entity, unicellular or multicellular, subject to the laws of the physical world and to the control by the systems that express the information contained in it.