Define the theme environment

From merriam webster:

1 : the circumstances, objects,or conditions by which one is surrounded

2 a : the complex of physical, chemical, and biotic factors (as climate, soil, and living things) that act upon an organism or an ecological community and ultimately determine its form and survival b : the aggregate of social and cultural conditions that influence the life of an individual or community
3 : the position or characteristic position of a linguistic element in a sequence
4 : a computer interface from which various tasks can be performed

url :http://www.merriam-webster.com/dictionary/environment

From dictionary.com :

.	the aggregate of surrounding things, conditions, or influences; surroundings; milieu.

2.	Ecology. the air, water, minerals, organisms, and all other external factors surrounding and affecting a given organism at any time.

3.	the social and cultural forces that shape the life of a person or a population.

4.	Computers. the hardware or software configuration, or the mode of operation, of a computer system: In a time-sharing environment, transactions are processed as they occur.

5.	an indoor or outdoor setting that is characterized by the presence of environmental art that is itself designed to be site-specific.

http://dictionary.reference.com/browse/environment

Overall definition : It is our surroundings that we live in. eg : a quiet environment.