The Lemmy app we are using on our phones needs to download content from Lemmy so it can be displayed to us. Lemmy might just have one big file full of links, but that’s annoying to have to write code to handle. Or it might have a folder full of files where each file is a post, but that’s also a bit annoying to write code to manage.
It (probably) uses a local SQLite database to store all of the cached posts.
Conceptually, a database is just a place to store things, just like a big text file. The database just handles a lot of the grunt work for you and makes it easier to search, organize, and filter the data.
So anywhere there is data, there could be a database.
A Windows VM running Windows terminal, SSH’d back into the host, obviously.
Honestly I stick with whatever the default is and never had a problem that led me to find anything else.