Nelson DeMille is a person who writes stories for you to read. He uses his imagination to come up with exciting adventures that people like to read about. These adventures can be about detectives solving crimes, soldiers fighting in wars, or people travelling to different places and having to face challenges.
When you read a book by Nelson DeMille, you get to imagine the story in your head and go on an adventure in your mind. It's like watching a movie, but you get to make up what the characters look like and how they act.
Sometimes Nelson DeMille's books are very long, but don't worry, he uses big words but he explains them so you can understand. This is called "vocabulary" which means the words we use to talk or write.
In summary, Nelson DeMille is a person who uses his imagination to write exciting adventures for you to read, and he helps you understand big words by explaining them in a way that's easy for you to understand.