Can imessage only send messages to each other between Apple phones?

Imessage can not only send messages to each other between Apple phones. Features are:

1) It is a messaging service provided by Apple, which can send messages to each other on iPhone, iPod Touch, iPad and Mac through the network.

2) can transmit text, video, pictures, etc.

3) You can quickly find out whether the other party uses imessage, and distinguish whether to use iMessage or SMS by message color.

4) You can confirm whether the other party has read the message by "sending a read receipt", or you can turn off imessage by setting and only use SMS.