Quick meaning
An automatic copy of your phone's data saved to an online server so it can be restored if your device is lost or broken.
Think of it like this
Like photocopying all your important documents and keeping the copies in a bank vault.
Where you may see this
You may see this inside app stores, app settings, software updates, and install instructions.
Why it matters
Knowing the term helps you understand what an app is asking you to do before you tap, install, or change anything.
Say it simply
Cloud Backup means: An automatic copy of your phone's data saved to an online server so it can be restored if your device is lost or broken.