Folder (element type)
Some analyses produce folders which have special properties. For example, Site search on gene set produces folder with special icon . When you double-click on it, the summary table produced by an analysis is opened. Such folders are still useful as general-purpose folders (you can put your own elements there, create subfolders, etc.)
When you export the folder, you will be prompted for export format. After that a ZIP-archive will be created containing all the folder elements (including the elements from the subfolders) which can be exported in the selected format.