Blank verse is a form of verse that uses iambic pentameter. That is the relationship that exists between iambic pentameter and blank verse.
Blank verse is poetry that is generally written in iambic pentameter, which is the most common type of metric line, at least in English poetry. In that way, iambic pentameter is closely related to rhythm. One of the most important characteristics of blank verse poetry is that it does not have a fixed number of lines; therefore, it is mainly used in dramatic monologues. Famous writers such as William Shakespeare and John Keats resorted to blank verse in their works.