Green computing is an emergent technology in the field of computer science and engineering which provides green information. It is largely used to protect environment by optimize energy consumption. To increase energy effectively and to reduce the use of hazardous materials are the two main goals of green computing. Green computing is the concept which is trying to confine this by inventing new methods that would reduce energy and making less population. This paper focuses on green computing techniques in order to achieve low power consumptions and power saving..