What do you think when you receive the echo message?

After receiving the echo message, click the SMS software on the mobile phone to view it, provided that both mobile phones are Apple phones.

Short message, short for SMS, refers to text or digital information sent or received directly by users through mobile phones or other telecommunication terminals. The number of characters that users can receive and send short messages at a time. Short message is a telecommunication service accompanying digital mobile communication system, which transmits text or digital short message through signaling channel and signaling network of mobile communication system, and belongs to non-real-time and non-voice data communication service.

The inventor of mobile phone short message is Finnish. Because Nordic people are sensitive and don't like to express by phone, they invented short message on a whim. Some people on the Internet say that the inventor of SMS is Marty Cooper, an American who works for Motorola, but he invented the mobile phone, not SMS. Voice messages can leave messages to friends and relatives by recording your own voice.

Voice short message service refers to recording what you want to say through fixed telephone, PHS or mobile phone and sending it to one or more users so that they can listen to your message. At the same time, you can also receive, forward, query, reply and request voice messages according to the prompt tone of the mobile phone. It makes up for the shortcomings that traditional short messages are difficult to transmit sound and inconvenient to input information.