During the usage of an editor a user can upload files like images, videos, ... into a textarea. This files are stored in the background and can be visible in the textarea.

When you delete the visible image in the textarea the file is still be stored in the context of the textarea. You can access such files in the atto editor by using the "manage files" icon and delete them but this is not very comfortable.

In addition to the atto orphaned plugin that shows the orphaned files just in time during the usage of the atto editor a report with an overview about orphaned files in a course can be helpfull.

This plugin adds for teachers a menu in each course that leads to a report that shows a list of such orphaned files sorted by coursesections.

Here is the link to the report plugin: https://moodle.org/plugins/report_sphorphanedfiles

Also helpfull: https://moodle.org/plugins/atto_orphaned that shows orhaned files during usage of the atto editor