What is the difference between prose and blank verse?
Blank verse has a rhythmic pattern, which prose does not have.
Prose is normal writing, as in letters, text books or novels, where the writer only needs to worry about the best words for conveying his/her meaning. In blank verse the words have to follow a pattern or rhythm, with the same number of syllables in each line. See Blank verse for a more detailed explanation.
Much of Shakespeare is written in blank verse.