What do you mean by royalty-free?

Royalty-free grants convenient and unlimited use to all video clips and images used in professional design projects meaning no royalty hassles.
Pay once and forget the headaches associated with royalty-based pricing. There's no need to worry about extra costs based on usage. These video clips and images can be used as many times or as in as many ways as the user sees fit and users can alter them without seeking permission.