Auto data switching is a super useful feature if you use two SIMs (either two physical SIM cards or combination of a physical SIM and eSIM) in your device. With auto data switching, you can change between two lines of data connectivity when on a phone call.

If you turn on allow mobile data switching, then while you're on a voice call on your voice-only number, that number will switch to using voice and data – as the name suggests – automatically. This will let you use both voice and data while on the call. If you turn off Allow Mobile Switching and you're active on a voice line that isn't your designated mobile data line, then mobile data won't work when you're on the call.

Got it? Great. We lost track after the first sentence.