Two versions of the same software
There are two types of Nintendo Switch games. A reseller version and a downloadable version. The content of the game will be the same no matter which version you play.
Retail version

The retail version of a program is the physical copy that you can buy in stores and the like.
Unpack the game and insert it into the Nintendo Switch console to play the reseller version of an application.
Download version
You can purchase the downloadable version of an application in the Nintendo eShop. You can download the application to the Nintendo Switch console or to a microSD card..
Fire Emblem Collection
Kirby Collection
Metroid Collection
Splatoon Collection
Super Mario Bros. 30th Anniversary Collection
Super Smash Bros. Collection
The Legend of Zelda Collection