Definitely not! The term sounds as if you own all rights for the music with a one-time license, which is simply not true.
If you buy royalty-free music on archive music platforms, you pay a one-time fee for the necessary exploitation rights and the sync-right to use (exploit) the music and combine (sync) it with your film. You can then use this music for a flat fee X€ on all purchased media with your film. The platforms in turn have of course clarified these rights with the external artists (the creators) in advance so that you don't have to do this anymore. This means that the usual buyout negotiations between you and the composer are no longer necessary. This is often called "royalty-free" in the end.
But then it can still happen that customers are suddenly asked by collecting societies to pay for "royalty free music", because the music is not automatically COPYRIGHT-FREE! Quite the contrary:
The vast majority of artists and composers are members of a collecting society like GEMA. Other such P.R.O.s (Performance Rights Organisations) besides GEMA are ASCAP & BMI (USA), SOCAN (Canada) or PRS (UK). As P.R.O. Member (composer, author) you are obliged to register all your works.
If one buys music, in many cases it will also be subject to GEMA and will cost the customer money afterwards, or more precisely: it will cost him "P.R.O. ROYALTIES", that is, copyright royalties.
And here lies the great danger of confusion: because the term "royalty" designates both rights: both exploitation rights and copyright royalties. And so royalty-free music can end up costing royalties.
To end this confusion I decided to offer my composed music for the area Online & Events (internal & external performances) completely and really royalty-free: with one license, worldwide, mostly unlimited in time and without any subsequent GEMA. This is contemporary for me and simplifies licensing enormously. Compared to archives, you get a completely customized composition, at more attractive conditions, without a license jungle, without the risk of subsequent billing. If you want more information about this, please write me without obligation firstname.lastname@example.org or call me.
If the contribution was helpful for you or if you have a wish for a new topic, I would be happy about a short comment!