There are two types of Nintendo Switch software: a retail version and a downloadable version. The contents of a game will be the same no matter which version you play.
The retail version of a software title is the physical copy that you can buy in shops, etc. To play the retail version of a software title, remove the game card from the packaging and insert it into the Nintendo Switch console.
You can purchase the downloadable version of a software title in Nintendo eShop on the console.
Distinct features of downloadable software
You don't have to worry about losing your game cards.
You can play different software without having to switch out the game cards.
How to purchase downloadable software
You can purchase downloadable software from Nintendo eShop on the HOME Menu.
Linking to a Nintendo Account is required to use Nintendo eShop.
You must have eShop funds in order to make a purchase on Nintendo eShop. You can add funds using a credit card or Nintendo eShop prepaid card.
How to play downloadable software
Download the software from Nintendo eShop. Once the download is complete, select the appropriate software icon on the HOME Menu to start the software.
The first time you use Nintendo eShop, the console you are using will automatically be registered as the active console for downloads for your Nintendo Account.