Steam Link is an app that allows the streaming of content from a computer running Steam to a personal mobile device. In other words, the app brings desktop gaming to your device.

What are the key features of Steam Link?

Synchronize: as mentioned above, thanks to this app, you can play games from your Steam library on your Android, Apple, or Raspberry Pi device.
Supported controllers: Xbox One Wired Controller, Xbox One S Controller, Xbox One Elite 2 Controller, Xbox 360 Wired Controller, Xbox 360 Wireless Controller for Windows, Sony Dualshock 4, Nintendo Switch Pro Controller (wired), Logitech Wireless Gamepad F310/F510/F710, Razer Kishi and Raiju Controllers, SteelSeries Stratus Duo, Keyboard, and mouse. The Steam Controller
Adjust your settings: to have the best performance quality, you can tune the streaming resolution and bitrate - to do this, go to the Advanced settings menu.
Technology: The Steam Link app is using the same Steam Remote Play technology used in the Steam Link hardware.

How to use Steam Link?

Using Steam Link is fairly easy: you first have to download and install the app on the device of your choice. Next, you have to pair the controller (check the supported controllers on the list above). Finally, connect to a computer running Steam on the same local network - and that’s it!