An auxiliary storage device refers to any type of storage device--except for the internal memory, usually referred to as RAM (Random Access Memory)--that is used to save information. From the moment you start typing a letter in Microsoft Word, for example, and until you click on "Save", your entire work is stored in RAM. However, once you power off your machine that work is completely erased, unless you had saved a copy on an auxiliary storage device, like an internal or an external hard disk drive, optical drives for CDs or DVDs, or a USB flash drive.
- Internal hard disk drive is the main auxiliary storage device that stores all of your data magnetically, including operating system files and folders, documents, music and video. You can think of the hard disc drive as a stack of disks mounted one on top of the other and placed in a sturdy case. They spin at high speeds to provide easy and fast access to stored data anywhere on a disk.
- External hard disk drives are used when the internal drive does not have any free space and you need to store more data. In addition, it is recommended that you always back up all of your data and the external hard drives become very useful as they can safely store large amounts of information. They can be connected by either USB or Firewire connection to a computer and can even be connected with each other in case you need several additional hard drives at the same time.
- An optical drive uses lasers to store and read data on CDs and DVDs. It basically burns a series of bumps and dips on a disc, which are associated with ones and zeros. Then this same drive can interpret the series of ones and zeros into data that can be displayed on your monitors. There are a few different types of both CD and DVD disks, but the main two types include R and RW, which stand for Recordable (but you can write information on it just once) and Re-Writable (meaning you can record data over and over again).
- A USB flash memory storage device is also portable and can be carried around on a key chain. This type of a secondary storage device has become incredibly popular due to the very small size of the device compared to the amount of data it can store (in most cases, more than CDs or DVDs). Data can be easily read using the USB (Universal Serial Bus) interface that now comes standard with most computers.
- There is a great variety of different auxiliary storage devices, some of which have become obsolete. You might still remember the tape drives that used reels of tape to store data or the 3.5 inch floppy drives that could store only minimal amounts of information. But, as we have seen with the rapid development of USB flash memory drives and SD memory cards (usually used in photo cameras), the modern technology doesn't stay still, allowing us to store more and more data onto smaller and smaller devices
