Computer Tip What is my Computer Hard Drive

Learn about the computer..


So What is my Computer Hard Drive?


Benjamin J Caruana  Whittlesea U3A Inc

Hard Drive

The computer hard drive is primarily used for two purposes:

First and foremost it is used to house the computer Operating System and

Secondly is used as the primary storage area for your computer software and files.

The hard drive is a mechanical device that contains magnetised disks (platters) that can be written to and read from. Both writing and reading is performed by an arm (actuator) which moves across the disk as the disk is spun around.

Not all hard drives spin at the same speed as the rate that they are spun is dependent on the makeup of the actual hard drive, the speed being measured in revolutions per minute (rpm), and the higher the speed the faster will be the operating speed of the hard drive.

NOTE: There are some hard drives known as SSD’s (Solid State Drive) that do not have any moving parts and are most commonly used in laptop computer. Although SSD’s and USB’s use NAND (Negated AND or NOT AND) flash memory to store their data, the technology used is different and it should be noted that SSD’s are more costly, more reliable and more efficient that USB’s.

Hard Drive Size

The hard drive size is NOT  referring to ist physical structure, that is – size and weight, but to the amount of data (Megabyte, Gigabyte) that it can store.

What does this really mean? If one byte is one letter, for example – A then:

A kilobyte is equal to 1000 (1024) letters: a Megabyte is equal to 1,000,000 (1,048,576) letters and a Gigabyte is equal to 1,000,000,000 (1,000,073,824) letters.

NOTE: the values in brackets refer to the actual size as there is actually 1024 bytes in a kilobyte.


Now these may seem like huge amounts of storage capacity, but medium sized image (photo) would be approximately 250 kilobytes, which bring the figures above into proper perspective, that is – if your storage was only 1 Megabyte then you could only store 4 pictures.