Introduction of Environment

The natural environment, all living and non-living things that occur naturally on Earth,Environment (biophysical), the physical and biological factors along with their chemical interactions that affect an organism Environment (systems), the surroundings of a physical system that may interact with the system by exchanging mass, energy, or other properties                                        

                                            source:http://en.wikipedia.org/wiki/Environment

An environment is a complex of external factors that acts on a system and determines its course and form of existence. An environment may be thought of as a superset, of which the given system is a subset. An environment may have one or more parameters, physical or otherwise. The environment of a given system must necessarily interact with that system

                                                                    source:http://www.wordiq.com/definition/Environment

source:http://www.rogerscorp.com/images/homepage/greeninitiative.jpg