Using Imessage
You can use the Messages app on your iPhone, iPad, or iPod touch to send messages. Those messages are sent as iMessage or SMS/MMS. Learn more about the difference between the message types.
IMessage is the Apple messaging service you get automatically with your Apple ID. If Messages asks you to sign in, use the same Apple ID that you use with Messages on your iPhone and other devices. It's usually the same Apple ID that you use for iCloud, the iTunes Store, the App Store, and the account you created when you first set up your Mac.
IMessages are texts, photos, or videos that you send to another iPhone, iPad, iPod touch, or Mac over Wi-Fi or cellular-data networks. These messages are always encrypted and appear in blue text bubbles. To turn iMessage on or off, go to Settings Messages. Dec 17, 2019 iMessage lets you send and receive SMS-like text messages, and MMS-style multimedia messages just like a phone through your iCloud account. Instead of just a phone number, however, it can use your email address, and it only works with other iPads, iPhones, and Macs.
iMessage
iMessages are texts, photos, or videos that you send to another iPhone, iPad, iPod touch, or Mac over Wi-Fi or cellular-data networks. These messages are always encrypted and appear in blue text bubbles. To turn iMessage on or off, go to Settings > Messages.
SMS/MMS
If you aren’t using iMessage, you can use SMS/MMS. These messages are texts and photos that you send to other cell phones or another iPhone, iPad, or iPod touch. SMS/MMS messages aren't encrypted and appear in green text bubbles on your device.
To use SMS/MMS on an iPhone, you need a text-messaging plan. Contact your wireless carrier for more information. You can also set up your other Apple devices to send and receive messages from any Apple device.
Using Imessage On Iphone
Using Imessage On Mac
If Wi-Fi is unavailable, iMessages will be sent over cellular data. Cellular data rates might apply.