Now that we've had a good look at non-volatile storage including tape storage and flash storage, lets go a bit deeper into the world of hard disk drives, which serve as fixed storage media. I'll try to keep things simple and short by focusing mainly on the knowledge necessary for forensics investigators in particular.

Hard disk drive technology has certainly come a long way from the monstrous storage devices first seen in IBM mainframes, and are now more compact, faster, and more affordable, with capacities in the terabytes.

Although the newer solid-state drives use the same type of memory found in flash memory devices, they are still a bit costly when compared to mechanical drives. This perhaps may be one of the contributing factors when wondering why older mechanical drive technology is still being used. Mechanical drives consist of moving parts including platters, an actuator arm, and a very powerful magnet. Although it is very common to still find these mechanical HDDs in today's laptops and hard drives, they are much slower than the newer solid-state drives, which have no moving parts and look very similar to the chipset of a USB flash drive.

In your forensics investigations and adventures, you may come across or be presented with older HDDs that can have different interfaces and use different cable technologies to connect to motherboards. Let's have a look, shall we?