Here's an introduction to the types of data that can be saved on Nintendo Switch and the different ways you can manage that data.
Types of data
Screenshots taken using Capture Button
What is software data?
Software data includes downloadable versions of software, downloadable content and update data. It doesn't include save data.
Save destinations for data
The data mentioned above can be saved in the following locations:
The console's system memory
A microSD card
The possible save destinations differ depending on the type of data.
This data is saved to a microSD card if one is inserted and will be saved to the system memory if the microSD card is full.
You can select a save destination for screenshots via System Settings ⇒ Data Management ⇒ Save Data/Screenshots ⇒ Manage Screenshots.
This data is saved in the console's system memory. Even if you are playing the retail version of a game, this data will not be saved to the game card. It cannot be saved to a microSD card either.
Managing software data
On Nintendo Switch, you can archive software data to clear up free space in a given save destination. Only save data and the icon on the HOME Menu will remain for archived software.
If you would like to archive software, select that software on the HOME Menu, press the + or - Button and then select Data Management ⇒ Archive Software.
Only the icon on the HOME Menu will remain for archived software. An icon will display before the software name to show that it has been archived.
You can select this icon to redownload the software. Redownloading may not be possible for software that is no longer being distributed.
If you want to delete the software icon, too
Open the options menu for the software you'd like to delete, then select Data Management ⇒ Delete Software. Save data will not be deleted.
Managing save data/screenshots
Open Album on the HOME Menu, then press [X Button] on the list of screenshots to select images to delete.
If you'd like to manage all of your screenshots at once, go to System Settings ⇒ Data Management ⇒ Save Data/Screenshots ⇒ Manage Screenshots. There you can delete all of your screenshots or copy data between the microSD card and the system memory.
All of your save data will be saved in the system memory. You can delete save data for each individual software by selecting System Settings ⇒ Data Management ⇒ Save Data/Screenshots ⇒ Delete Save Data.
Deleting all data
You can delete all data and return the Nintendo Switch console to the state you bought it in by restoring factory settings. All information saved on the Nintendo Switch console, including user information, internet settings and game-related news articles, will be deleted.