Royalty-free describes intellectual property that can be used without having to pay royalties. Once a one-time fee is paid for a royalty-free license, the buyer is free to use it without having to pay recurring fees to the intellectual property owner.
While a royalty-free license gives a person the right to use it, the intellectual property still belongs to the original owner. Anyone who buys a royalty-free license is entitled to use the same content. In other words, royalty-free content is not exclusive.
However, there are many perks of using royalty-free content. A buyer does not need to attribute the owner and each content can be used as many times as desired in as many projects as possible.