iMessage is an instant messaging service found in Apple-products only, which uses the device’s mundane messages infrastructure coupled with internet connection to send messages.
As the service uses internet connection to send messages, the sender’s SMS data is not used.
Soon, iMessage will be made available publicly on Windows computers, which will make it easy for iPhone users who use Windows computers to send and receive text messages without having to reach for their iPhone.
This will be made possible by Zen, a third-party solution developed by Amnesia Software. The software will be available for Windows and Linux computers and will be the first cross-platform and secure iMessage enabler.
The developers of Zen are planning to release the software in March 2020. It will as well be launched on a subscription-based model.