I can't find any good resources about how this kind of authentication scheme works where you open an app on your TV (Plex, Youtube,...) and they show you a code (optional there's also a QR code) and then you go to their website, enter their code and then your TV is logged in.
How does this work and what is it called so I can read more?
The sites they ask you to open and enter the code usually look like this:
Thanks!