1. eSim Cards
ESim are integrated chips that function as a sim card. On the pro side, they are rewritable, so you can change carriers fairly easily. If you travel a lot, you may be able to eliminate roaming charges.
Cons — if you regularly change phones, eSim is not removeable. You will have to transfer all the data onto a new card. If you like to borrow someone else’s phone and use your sim card, you won’t be able to do that.