Why is iphone SMS green?

There are two ways to send and receive iPhone SMS.

One is the ordinary short message sent by the operator, so the short message sent is green. For this kind of short message, the operator charges.

And the SMS sent by iMessage, blue, free. Sending through the network, the effect is equivalent to QQ, WeChat, MSN and other tools and software, but iMessage is limited to the communication between Apple devices, and currently does not support non-iOS products.

IMessage is an instant messaging software launched by Apple, which can send short messages, videos and so on. It has high security. IMessage is different from SMS/MMS service of operators. Users only need the data support of WiFi or cellular data network to complete communication. IMessage uses the new message reminder system of iOS and Mac os to directly push information to the other party's screen, regardless of whether the other party is in the game or locked. If both parties are using iMessage, you can even see the state of each other's speech.