Alister Education / Computer Education / Storage Devices
COMPUTER EDUCATION · LESSON 05

Storage Devices

Learn how computers store files, compare HDD and SSD, and understand common storage options and capacity units.

BeginnerStorage6 min
CACHERAMSTORAGEAs a simple rule: faster memory is usually smaller and closer to the CPU.

What is storage?

Storage is used to keep files, programs and other data for longer periods, even when the computer is turned off.

HDD and SSD

HDD

Uses spinning magnetic disks and a moving read/write head. It can offer large capacity at a lower cost, but it is mechanical.

SSD

Uses flash memory and has no moving mechanical parts. It is generally faster and more resistant to physical shock than an HDD.

Other storage

Capacity units

Common units include KB, MB, GB and TB. In everyday device specifications, manufacturers commonly use decimal units, while operating systems may display capacity using binary-based measurements or labels such as GiB.

Good habit: Keep important files in more than one place. A second copy is a backup; a second copy on the same failing drive is not a reliable backup.