Hard disc drives (HDD)

This is your permanent storage, where everything is saved to,  so your operating system,  games and other general files.  Your hard drive is a box, with a magnetic tape inside where data is stored on, this data can last for long periods of time however it can be damaged if exposed to magnets or left for long periods of time (over 10). Most users only have one hard drive, but some choose to run them simultaneously, in a RAID configuration. This makes them act as a single hard drive, aswell as making them transfer data faster. If you wish to learn more about this please go to it's dedicated page.

Which hard drive should I buy?

When purchasing a hard drive most people just look for their capacity (how much data that they can hold),  but there are other important things to consider such as the rotation speed, measured in RPM (rotations per minute), the data transfer speed (mb per second) and the ammount of noise produced, which can only really be found out by reviews.