Users can choose a type and a mode for each disk.
There are three types and three modes. Each type can be configured with any one of the three modes and vice versa. A virtual disk is a file on the host file system that appears as a physical disk drive to a guest operating system. The file system can be on the host machine or on a remote computer. When you configure a virtual machine with a virtual disk, you can install a new operating system onto the disk file without the need to repartition a physical disk or reboot the host.