Why does Apple's mobile phone need to be connected to the Internet to send text messages?

Apple's mobile phone texting is generally not connected to the internet.

If imessage is turned on, texting between Apple phones is free, and it can't be sent without the network. If you want to send an ordinary short message with Apple when there is no network, just check the check box in Settings-Information to send it as a short message, so it can also be sent as an ordinary short message when the network is not good.

Extended data:

Imessage is an instant messaging software launched by Apple on 20 1 1. Imessage has the functions of sending text information, location information, photos, videos and so on.

With iMessage, you can send and receive messages with any Mac user who uses iPad, iPhone, iPod touch or Mountain Lion, as well as send photos, videos, location information and contact information. If you have more than one Apple device, iMessage can keep an uninterrupted conversation on all devices. In addition, you can send text messages, photos and videos to other mobile phones through the cellular network. You can even ask Siri to text you. Just say "Tell Xiaoli I'm on my way" and Siri will help you write and send messages.