In every working computer there is a hard disk drive. The hard disk drive is often abbreviated as (HDD). Unlike the RAM, HDD is a non-volatile memory hardware device. The HDD stores and retrieves data thats is in the computer permanently. It acts as the secondary storage device. Every so often HDD is confused with the SDD. To learn more about SDD click here. Hard disks are circular and flat. Coated in a magnetic material the HDD consists of aluminum or glass. These disks often called platters receive data from a magnetic head which writes it onto the actual disk.

Everything stored on the HDD is kept in bytes. If the CPU requests something to be sent, the HDD springs into action and locates where on the disk it is. Once the HDD locates the data, the data is transmitted in bytes back to the CPU.

Today an HDD costs around 50-200 dollars. If one were to buy a more expensive HDD it would only be more efficient and faster than the normal ones. On the HDD there is an incredibly efficient arm which moves from the mechanism on the top left to the disk and back fifty times a second. As technology advances every day the HDD just becomes better; now we have more platters to maximize the productivity.
Today the HDD is small, affordable, and has a large storage capacity. In the early 80s none of this was true. In 1980 IBM created a hard drive that was capable of holding one gigabyte. By 1992 the hard drive could hold two whole gigabytes! Finally by 2006 the hard drive held 12 gigabytes on a one inch hard drive. HDDs are very useful in our computer but gradually SDDs are being used more and more. Its astonishing to think that a one gigabyte HDD cost around 500,00$ in the 1980s.