Quick meaning
A feature that keeps your preferences and data the same across all your devices automatically.
Think of it like this
Like having your reading glasses prescription updated in all your pairs at once.
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
Sync Settings means: A feature that keeps your preferences and data the same across all your devices automatically.