Are biographies fictional or non-fictional?

Biographies are supposed to be non-fictional, but there are some people who say that there are some biographies that may come with stories that are not true in order to make the biography more interesting for a lot of people. A biography has to detail the things that a person has experienced throughout his/her life, and the details should be based on actual facts; otherwise, it would be like creating fan fiction.

A biography can be fun to write for authors who are generally interested in the person that they are writing about. They can make the stories that the person has experienced seem more fun or dramatic without altering the facts.