Categories, tags and authors
Categories
Categories are the main sections of a site (News, Guides, Football…). They can be nested: a sub-category has a parent. Manage them under Categories. Websites can filter by them (/api/posts?category=news), and they can have their own pages and sitemap entries when a category URL is set under SEO.
Tags
Tags are looser keywords. Add them while editing an item: pick existing ones, or type new ones separated by commas in New tags.
Authors
Authors are the people credited on content, with a name, photo, bio and social links. They are separate from user logins, so you can credit guest writers who never sign in. Manage them under Authors, then choose one on each item.
The photo comes from the media library (upload it there first, then click Choose…). A square image works best, since websites usually show it as a small circle by the byline. Websites can list an author's stories with /api/posts?author= and the author's slug.