It can be helpful to view assets that aren't in any folders, if you want to keep your Dash organised and ensure all assets are in at least one folder. This is especially important if you use permissions to control which users can see which assets.
To view assets not in any folders:
Navigate to your browse page
Open the filters panel on the left hand side
Expand the Folders filter
At the bottom of the folders list, click "Not in any folders"
This will show you all assets in your Dash (that you have permission to see) that aren't in any folders. You can now update these assets and move them into folders if you wish.