Is it necessary to enable iMessage?

Apple’s iMessage needs to be turned on.

iMessage is an instant messaging software launched by Apple. It can send text messages, videos, etc. with good security. Different from the operator's SMS/MMS service, users only need data support through WiFi or cellular data network to complete communication.

On March 10, 2020, according to MacRumors, Apple is internally testing new features of iMessage, including mentioning "@" and withdrawing messages. These features may be released as soon as iOS 14.

Function:

Use iMessage to send and receive messages to and from any user using iPad, iPhone, iPod touch or Mac user running Mountain Lion. You can also send photos, videos, and location information. and contact information.

If you have more than one Apple device, iMessage can keep the conversation going on all of them. And can send text messages, photos and videos to other phones over cellular networks. You can even send text messages with the help of Siri. Just say "Tell Lily I'm on my way" and Siri will compose and send the message.