What does imeesage short message mean?

You can think that Apple's SMS software is an app similar to WeChat. When your mobile phone sends a text message to someone else, the SMS app will detect whether someone else's mobile phone is an Apple phone, and if it is, it will be sent in the form of iMessage. This kind of information does not need to pay the SMS fee to China Mobile or China Unicom, but only needs a little traffic (if it is sent in a place with Wifi, there is no need for traffic). By default, the iMessage function is turned on, which you can check in the settings and information of Apple's mobile phone.