What is the difference between prose and novel?

The difference between "prose" and "novel" comes from the different natures of each. "Prose" is a particular style of writing, to be distinguished from, for example, a poetic style. On the other hand, a "novel" is a particular genre of literature. As a narrative of some kind, novels are constructed through the use (partial or whole) of a prose style, which of course can be used in the construction of other kinds of literature, whether letters, or blogs, or essays, etc.