A novel is a type of book of fiction. It tells a fictional story, which also means it has a general format of sorts, and has an average and/or at least a minimum length (the specific requirements of which I am currently uncertain of).
A novel is a book of fiction. Not all books are fiction.
Do you remember a favorite Breakfast cereal you had as a child but is no longer made . . . What was it? I will post mine under the question.
Here's the Cereal I long for . . Not sure why, it must have around a particular time in my life I want to hold on to.