Secondary Storage

For most of us, our programs and files are stored on the internal hard drive of our computers. This applies whether we are talking about laptops, desktops, tablets or games consoles. However, we may require additional secondary storage to back up our files or so they are portable. These are sometimes called ‘backing storage’.

Storage Media

Optical Disks

Lasers are used to ‘burn’ data to a disc. These discs contain tiny bumps called pits and flat sections called lands. To read the data back, lasers are pointed at the disc as it rotates – if the light is reflected at the sensor (lands), it is read as a 1, if the light is not reflected (pits), it is read as a 0.

Magnetic Storage

Traditional hard disc drives use metal discs (or platters) to store data. This discs are essentially contain billions of magnetised pins that are magnetised to either positive or negative, representing 1 or 0 in binary. The read-write head moves across the disc as it rotates (A hard knock or even some dust could result in the read write head not working properly). Hard disk drives also make noise as the discs spin and the read-write head making them less desirable than silent solid state drives.

Tapes and floppy discs use the same concept, with a magnetised surface applied to the plastic tape or disc.


Solid State Drives do not require moving parts and are so more durable than Hard Disk Drives. Billions of tiny transistor switches are used to represent data based on whether or not they allow an electrical current to pass through.

Cloud Storage

Cloud storage refers to any data stored on servers connected to the internet rather than being saved locally on the device or on servers in the building.

Cloud Storage

%d bloggers like this: