Virtualization can be defined as one physical computer performing the same function as multiple computers.

A single highly-specified computer is loaded with special software which allows resources to be managed & shared

For example if a company has five servers their usage could be analysed as follows:

• 5 separate physical computers running 5 different tasks. (File Server, Web Server, Database server etc;)
• 5 power supplies drawing power to run those 5 machines.
• 5 different pieces of hardware containing multiple components with the potential for each one to fail.
• 5 separate machines which cannot collaborate, so lots of resource will be unused such as computer memory, processing power and storage.

With a Virtualized system a company can:

• Have many ‘virtual’ computers running simultaneously on a single physical machine
• Save money on the purchase of hardware as less computers are needed , perhaps one or two highly specified machines could replace 5 or 6 individual computers
• Consolidate management of the machines therefore saving staffing costs and time managing the system
• Reduce energy consumption as there are less computers to power
• Make much more efficient use of resources as the new machine(s) will be able to share those resources.
• Improve redundancy: a virtualized system will improve levels of redundancy, virtual machines can be restored in seconds and with multiple servers the computing load can shared between machines, a failure in one machine will not lead to the failure of any of the ‘virtualised’ computers.

Most computers operate using as little as 4-7% of their resources. In a virtualized environment greater savings can be made in power consumption, physical space and resource utilization, multiple physical machines can be consolidated into fewer machines which permits resource to be allocated efficiently thereby reducing waste, there is less hardware to go wrong and there will be a vastly improved levels of redundancy.