Jargon Buster
Plain English meaning, where you may see it, and what to read next if this word still feels unfamiliar.
Quick meaning
The main software that runs your device.
Think of it like this
Like the manager of a busy office.
Where you may see this
You may hear this when buying a device, asking for repairs, or checking phone and computer settings.
Why it matters
Understanding the hardware term helps you choose the right device and explain problems more clearly when asking for help.
Say it simply
Operating System means: The main software that runs your device.
Keep going
Directly related
More in Devices & Hardware
Accelerometer
A sensor that measures movement and acceleration, used for step counting, screen rotation, and motion-based games.
Action Button
A customisable physical button on newer iPhones that can be set to perform a chosen function with one press.
Aeroplane Mode
A setting that disables all wireless connections — calls, data, Wi-Fi, and Bluetooth — while keeping the device on.
Ambient Light Sensor
A sensor in your phone that detects the brightness of your surroundings and adjusts screen brightness automatically.
Battery
The power source for a mobile device.
BIOS
The first programme that runs when a computer starts, before the operating system loads.
More O terms
Offline Mode
The ability to use an app or access content without an internet connection.
Offline Page
A page stored on your device that loads when you have no internet connection.
OLED Display
A screen technology where each pixel produces its own light, giving deeper blacks and more vibrant colours.
Onboarding
The process of guiding a new user through an app's features for the first time.
Online Account
Your personal space on a website or app.
Online Forum
A website where people post questions and answers on a topic, and others can reply in a thread.