Quick meaning
Deleting temporary files stored by an app to free up space and fix performance issues.
Think of it like this
Like clearing the clutter from a desk so there is space to work properly again.
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
Clear Cache means: Deleting temporary files stored by an app to free up space and fix performance issues.