The Kaltura Media Gallery is a shared media gallery for the course that both instructors and students can access and upload their media into. This prevents the need of having to create separate Moodle activities in your course to embed Kaltura media into.
The Kaltura Media Gallery for your course does not take up any additional space when backing up or restoring your course. The Media Gallery pulls the video directly from your personal Kaltura gallery (My Media) and displays it in the Course Media Gallery. It is not transferred over with a course backup because each course has its own media gallery. This eliminates potential storage or size issues that can arise when embedding a number of media files into your Moodle course.