Installing, offloading, and the permission questions people actually ask — including what an app can see in the background.
Start with the question you actually have. If it is about the background toggle, read them in this order:
- What Is Background App Refresh? — what the switch controls, and the four different things iOS calls "background"
- What Happens When You Turn Off Background App Refresh? — what actually stops, by app type, and whether your problem is caused by this switch at all
- Does Turning Off Background App Refresh Stop Notifications? — why alerts travel a separate path, and the one narrow exception
- Which Apps Should Keep Background App Refresh On? — the per-app decision rule, and the Wi-Fi only shortcut
For permissions, start with App Permissions Explained — what each option actually grants, and why limited photo access is a real answer rather than a half-measure — then run How to Audit App Permissions on iPhone to see what apps actually accessed rather than what you granted.
If you are looking for something specific, start with background app battery use.