Logical Drive– A section in the hard disk, appearing to be a separate drive in a directory structure. Logical drives are created on the extended partition of a hard disk. Out of 26 letters that exist for logical drives, the first three are reserved. Floppy disk drives have A and B reserved for them while C is reserved for the first primary DOS partition. This leaves 23 logical drives on ones extended partition. These drives are used to group directories and files usually.