Removable storage has been around almost as long as the computer itself. Early removable storage was based on magnetic tape like that used by an audio cassette. Before that, some computers even used paper punch cards to store information!
Portable Memory
There are several reasons why removable storage is useful:
* Commercial software
* Making back-up copies of important information
* Transporting data between two computers
* Storing software and information that you don't need to access constantly
* Copying information to give to someone else
* Securing information that you don't want anyone else to access
Modern removable storage devices offer an incredible number of options, with storage capacities ranging from the 1.44 megabytes (MB) of a standard floppy to the upwards of 20-gigabyte (GB) capacity of some portable drives. All of these devices fall into one of three categories:
* Magnetic storage
* Optical storage
* Solid-state storage