The difference between SMS sending and reading on Apple's mobile phone.

The recipients are different. The message sent by Apple's mobile phone shows that it has been successfully sent to the other party's mobile phone, indicating that the user who received the message did not read it, while the message displayed as read indicates that the other party not only received the message, but also read its message content. "Sent" and "Read" will only be displayed when both Apple phones send messages via IMessage. IMessage is an instant messaging software launched by Apple, which can send short messages, videos and so on. It has high security. Different from the SMS/MMS service of operators, users only need the data support of WiFi or cellular data network to complete communication, which means that both parties must be Apple phones to use this function.