Yes — in Darktable, a “collection” is not necessarily a physical folder. It’s usually a set of filters used to display images. The default collection type, “film roll,” generally corresponds to a folder on disk, but collections can also be based on tags, date/time taken, lens, and other metadata.

So if you want to split a large set into theme-based groups, you usually do not need to move files manually. A common approach is to tag the relevant photos, then view them as collections by tag. Images can belong to multiple collections this way.

You can also change how the Collections panel groups photos by clicking the label under “Collections” (such as “Film Roll” or “Folder”) and choosing another collection type like “tag” or “date-time taken.” The panel will then update to show your images grouped that way.

If a certain filtered view is useful, you can save it as a preset for quick access later.

Only move files into different folders if you specifically want to reorganize your storage on disk, not just your browsing inside Darktable.