Data Transfer

What if it’s the same SIM card?

will my old phone do what it needs to do without a sim in it?… because the sim will be in my new phone!.

I’m also curious about what exactly gets transferred? I can’t find the specific info anywhere.

photos and videos I’m assuming but what about voice memos, notes and apps etc.?

thanks

iPhones do not store any data on the SIM and hence having another SIM with another phone number actually does not matter at all.