Ipad and iphone send messages to each other with different ids. What are the conditions for sending messages to each other, and they are free?

So you will be free. You can fly in mobile phone mode, then connect wifi and ipad to wifi, then enter SMS mode and enter the id of the other party. The background color of the short message is blue. ~ ~ Pay attention to yourself when sending text messages on iphone. If the background color of the short message is green, it will be charged according to the short message. If the background color is blue, it will get iMessage. ~ ~ I hope I can help you ~ ~