The Archiving feature (Project) in Kdenlive allows you to copy all files required by the project (images, video clips, project files,...) to a folder, and alternatively to compress the whole into a tar.gz file., see
Archiving changes the project file to update the path of video clips to the archived versions.
This can be useful if you finished working on a project and want to keep a copy of it, or if you want to move a project from one computer to another.
The resulting tar.gz file can be opened directly in Kdenlive. Kdenlive will uncompress it to a location you specify before opening it.