Apple automatically sends text messages to its girlfriend.

In this case, two mobile phones should use the same Apple ID number. If you use the same Apple ID account, all Apple devices in the same account can receive information when using iMessage.

Messages sent by iMessage are blue, including contacts. The blue color shown in the figure below indicates that iMessage messages are allowed, and non-blue messages can only be sent by ordinary SMS. Sending and receiving information through iMessage is free.

The following figure shows the input screen that can send information with iMessage.

Ordinary SMS is shown below.