Joke Collection Website - Public benefit messages - Why can Apple receive text messages without a sim card?

Why can Apple receive text messages without a sim card?

There are two possibilities. First, this phone is connected to a WIFI network and uses chat tools such as Imassege to send short messages.

Secondly, this iphone is a number burning machine, and the information of the SIM card has been burned into the memory of the motherboard, so there is no need to use SIM, but the Iphone number burning machine has been cancelled since 4S.