An author who writes many books is considered prolific.
The word "prolific" often describes someone or something that creates a lot of content. It's commonly used to talk about writers who publish lots of stories, artists who produce many paintings, or musicians who release numerous albums. Imagine a writer who churns out bestseller after bestseller - we might call them prolific. The idea is that they're producing a lot of work, often at a rapid pace.
Fertile; producing offspring or fruit in abundance, applied to plants producing fruit, animals producing young, etc.
