Yes. The 'Stranger Things' book is a great piece of fiction. It expands on the strange and mysterious world of the Stranger Things universe. It has engaging characters and a plot full of twists and turns that keep you hooked from start to finish.
One of the main themes is friendship. Just like in the show, the characters in the book rely on their friendships to face the terrifying things in their town. Another theme is the battle between good and evil, as they fight against the strange forces from the Upside Down.
Definitely fiction. Stranger Things has elements like monsters and alternate dimensions that are not real. It's created for entertainment purposes and doesn't represent real-life events or people.
Definitely not. Stranger Things came into being as a TV production. It wasn't based on a pre-existing comic book. The success of the TV series might have inspired comic book spin-offs, but the initial idea was for the screen.