On July 1, 2019 Apple plans to shut down its Back to My Mac service. This let users set up a network of Macs that could be accessed remotely.
screen sharing
macOS: Using Screen Sharing Within Messages
If your friend is having problems on his Mac, you’ve gotta know that Messages has a built-in screen-sharing feature that’ll let you help from afar.
Screen Sharing Could Be a Thing in iOS 11
We don’t know how it will work yet, but have some speculation about the upcoming new feature.