same as "work-for-hire." The illustrator or author is paid a lump sum for their work, and gets no royalties.
A one-time payment, as opposed to a royalty fee which involves payments at regular intervals. Sometimes called work for hire.
One-time compensation that generally provides a lump sum for an author or illustrator's work in exchange for all rights. (This is in contrast to a contract that includes an advance and royalties.)