Energy efficiency is a major issue in cloud computing infrastructure. The large power consumption is mainly attributed to the large number of modern data centers operating within. Developing these data centers includes dynamically expanding their infrastructures to meet the ever-increasing demand for huge computation, large storage, and massive communication. Energy conservation through optimization of resources and management policies in the cloud are a viable solution. Using virtualization to save power and employing such practices as using Virtual Machines (VMs), server consolidation, and VM live migration.