Virtual machines are the key component in a virtual infrastructure. You can create virtual machines to add to the host inventory.
When you create a virtual machine, you associate it with a particular datastore and select an operating system and virtual hardware options. After you power on the virtual machine, it consumes resources dynamically as the workload increases, or returns resources dynamically as the workload decreases.
Every virtual machine has virtual devices that provide the same function as physical hardware. A virtual machine gets CPU and memory, access to storage, and network connectivity from the host it runs on.