Disks: An Overview
Disks belong to the category of Direct Access Storage Devices (DASDs) because they make it possible to access the data directly.
This is in contrast to Serial Devices (e.g., Magnetic Tapes) which allows only serial access [all the data before the one we are interested in has to be read or written in order].
Different Types of Disks:
- Hard Disk: High Capacity + Low Cost per bit.
- Floppy Disk: Cheap, but slow and holds little data. (zip disks: removable disk cartridges)
- Optical Disk (CD-ROM): Read Only, but holds a lot of data and can be reproduced cheaply. However, slow.