Nintendo has just dropped Nintendo Switch update 6.0.0 and it has some genuinely great features. Outside of the fact that it is necessary to access Nintendo Switch Online later today, it also brings us the ability to share digital games across to other consoles.
Much like how Sony handle it with the PS4, you’ll have a Primary Console which can play your digital games at any time (regardless of internet connection). You can then login with other consoles which can also download the digital games linked to that account but they must have a stable internet connection.
Also similar to how it works on the PS4, you can only be playing games on one console at a time. You can read more about how it works HERE.