Overlay File System

An overlay file system combines multiple sources (directories and files) into a single virtual directory.

• Directories with the same source path are merged - they contain all files from all sources.
• If there are files with the same path, only one file is shown, depending on the precedence of the sources. See also Wikipedia.

The different sources are like transparent layers in a painting application such as Adobe Photoshop. The non-transparent pixels (files) at a specific point (path) are stacked on top of each other, so that only the top-most opaque pixel is visible.

In Foldie, you can create, host overlays and browse them like an overlay file system.