For those who are unfamiliar, Steam Link is an app developed by Valve that allows users to stream games onto various devices, like from a computer to another computer, or from a computer to a phone. This will be useful for Mac users who might not be able to play certain games due to hardware restrictions or due to lack of Mac compatibility.
Since the processing of the game is done on another computer, it does away with some of the bottlenecks, which means that any computer should be able to play the game. Valve is recommending that gamers use a 5GHz WiFi connection or an Ethernet connection for the best possible quality.
Valve had debuted the Steam Link app a few years ago, but as Apple was kind of against streaming apps at that time, it did run into some issues. Those problems have since been sorted and if you want to get your hands on it, it is available through the Mac App Store.