Why are there two colors of SMS sent by iphone: green and blue?

Green and blue represent SMS messages sent and received by operators and Apple iMessage respectively. The former is our traditional short message, which is charged according to the number of short messages; The latter is free because information is sent through network traffic.

Blue SMS is a service provided by Apple for iOS devices that can send information for free through the network, namely iMessage message. Use iMessage, whether using wireless network or mobile network. When iMessage, the other party must also be an Apple product, such as iPad, iPhone and Mac.

Apple's iMessage service provides users with two major benefits: one is that they don't have to pay SMS fees to operators, and the other is that users can experience more SMS functions. For example, sharing geographical location, sending intercom language messages, checking the status of message delivery, and even checking whether the other party is returning messages to you.

Users can choose the way to send short messages through their own settings.

Extended data

Similar to MMS, iMessage not only allows users to send text to other iOS and OS X users via Wi-Fi, 2G, 3G or 4G LTE, but also can transmit documents, images, videos, locations, contact information and group information, thus providing standard SMS and multimedia SMS services for most devices with iOS 5 and above.

With iMessage, you can send and receive messages with any Mac user who uses iPad, iPhone, iPod touch or Mountain Lion, as well as send photos, videos, location information and contact information.

There are also some tips when using iMessage information. When you encounter network signals from time to time, there will be a problem that information cannot be sent. Therefore, in the setting interface of iMessage, that is, Settings-Info, it can be turned on as an option to send short messages.

In this way, when the network is not smooth, the system will automatically switch from iMessage to traditional SMS without delaying the sending of information. In addition, when sending an iMessage message, you can also switch by pressing and holding the message being sent and selecting the option to send it using the short message service.

Baidu encyclopedia: iMessage