In this article, the author collects some definitions and concepts related to green computing model for clouds. Greening your computing equipment is a low-risk way for your business to not only help the environment, but also to reduce costs. Reducing energy usage, which also reduces carbon-dioxide emissions and your energy bill, is the most effective thing you can do. Green computing can be defined as the efficient use of computing resources. Computing reduced power consumption is environmentally less expensive. It is also associated with the proper use of computing resources and plays a vital role in minimizing their dangerous impact on surroundings. The strength of public and community opinion shifting in favour of environmental responsibility is also growing rapidly. Computing is also an area of human activity in which there are real environmental savings to be made, some of which can be achieved by implementing relatively straightforward practical measures with existing hardware.