Narrative nonfiction is like telling a really cool story, but it's all true stuff! Two big things that make it special are that it has a plot (that means a sequence of events) and characters that grow or change, like how you'd find in a fun storybook. Plus, it has lots of colorful details and pictures in your mind that make you feel like you're right there when you're reading.
This makes narrative nonfiction different from other kinds of nonfiction, like when someone just gives you facts or tries to convince you of something. In those, they mostly just list information without painting a picture or making it feel like a story. In narrative nonfiction, it's all about making it exciting and interesting while still being real!