Global folders
A global folder is a collection that gathers images from anywhere in your library into one spot in the sidebar. It is where you build a reference board, a shortlist, or a folder of favorites that span a dozen projects.
Make one
Global folders live in the Smart Folders section. The first time you create one, Atlas asks where on disk to keep these collections. After that, click the plus and name it.
Fill it
Right-click any image, or a whole selection, and use Add to to drop it into a collection. Atlas copies the file into the collection's folder on disk and looks after the copy, so a global folder is real, openable files gathered in one place, with nothing to sync. The original stays where it was.
Manage it
Right-click a global folder to color it, give it an icon, add subfolders, or remove it. Removing the collection leaves the original images alone, and your collections show up in search and the All view like any other folder.