Tags are several words that describe your book. E.g, if I’m publishing a children's book, my tags will be something like: Children, children’s book, the story of Ada, Okon Ifeanyi.
So I also added the name of the author and each tag is separated by comma.
If I am uploading a romance book, I’ll use tags like: Romance, fiction, adult, a story of reckless love, Okon Ifeanyi.
You can add whatever number of tags you want.