Source: VMware.com
From a technical perspective it is a conversion of hardware devices into software resources so lets put that into human terms:
Think about your data center. You probably have number of physical server sitting in rack alongside other networking and storage devices. You may have many different types of servers because each server has its own operating system, applications and data.
They all have something in common though. They consume power. Unfortunately that’s not the only thing they have in common. Physical devices that use power also give out heat. Heat that, we need to get rid of, by cooling the data center. This too takes power and power costs us money. If we could figure out a means to break that cycle, we could save you money. Virtualization breaks that cycle.
Now let’s go back to the technical explanation. Virtualization converts the hardware in the software resources. That means that we can separate the server’s operating system and applications from underline hardware, presenting virtual hardware does the same job. The virtual hardware is actually software running within hardware called the hypervisor. We will talk more about hypervisors in module2. But for now you can think of hypervisor as a resource. Its job is to provide each virtual machine access to the underline physical resources. This enables multiple virtual machines to share access to the same hardware without even being aware of each other. That leads us to one of the most important advantages of virtualization i.e. consolidation.
Through Virtualization we can consolidate our servers into a fewer pieces of hardware by reducing the number of physical devices in the data center we can save money power and cooling. We can also save money on capital investments and management costs.
