What is a factory reset and when do you need it?

A factory reset erases everything on your phone — all apps, photos, messages, and files — and returns it to like-new condition. It's permanent and irreversible. Back up your data first.

A factory reset is a complete wipe of your phone. Everything gets deleted and your phone goes back to how it was when it left the factory. It's useful if you're giving away a phone or have a problem nothing else can fix. But it's permanent, so back up your data first.