Primary storage mediums are Hard Disk Drives (HDDs) and Solid State Drives (SSDs). They both store information all be it in different ways. These differences also determine storage durability and speed.
HDDs work by using spinning metal platters and passing heads with magnets of the top to read or write information stored as 0 and 1s. IBM created the first HDD for their computer in 1957, but it wasn’t until 1980 that Shugart Technology made and sold HDDs that become the standard for computers in the average household.
The platters which spin are measured in RPMs, the faster they spin the faster you can read/write data. The common speeds are 5400rpm, 5900rpm, 7200rpm. We don’t often find drives spinning faster, this is due to the turbulence of the air inside, as well as slight deformity of the platter.
The read/write heads on HDDs are small pieces of circuitry that can detect and create magnetic fields on the platter. The move over the spinning platter when the computer requests to read or write a file. However, files become fragmented meaning pieces of the files are not next to each other. This in turns causes read/write times to slow down. This is why we need to perform a defrag once a week to once a month depending on your usage.
There are many ways HDDs fail either the heads hit the platter or the motor spinning the platters slow down. The cause of each is either just age 3 to 6 years (depending on use) or sudden stop movement (i.e. being dropped). Desktop drives do tend to last longer than laptop drives due to this last point. Remember always shut down or put the laptop to sleep before moving the computer to reduce damage to the drive.
SSDs by contrast have no moving parts making them far more durable and faster. They store information in transistors called cells as Positive voltage (1) or No voltage (0). The voltage can be changed by a small amount to allow greater density of layers of information stored. The more levels an SSD has the more it can store but the slower it is to use and faster it wears out. The highest number of levels per cell is currently 4 (in 2020), Quad Level Cell (QLC).
HDDs and SSDs store information but neither are perfect. For our computers in the office we use SSDs but for our larger storage devices we use HDDs. It comes down to what you want. For most people we recomend HDDs due the fact when if it fails before the next time we see the computer there is a better chance of recovery. Though proactive protection of information that’s importatnt a back up should always be kept. A back up is well advised.
To read more about backups you can read our other post What are Backups, and Why you should.