Author editing is when someone goes through a piece of writing, like a book or an article, and makes changes to it to make it better. Imagine if you were drawing a picture, and someone came along and helped you make it look even better by changing some of the lines and colors. That's what author editing is like for a piece of writing.
The person doing the author editing might change words to make them sound better or help the meaning of the sentence be more clear. They might also fix mistakes, like spelling or grammar errors. It's kind of like having a personal helper to make sure your writing is the best it can be.
Sometimes when people are working on a big writing project, like a book, they might have someone else do author editing for them. This is because when you've been working on something for a long time, it can be hard to see mistakes or areas that need improvement. Having someone else do author editing can help make sure the writing is the best it can be before it's shared with others.