Dynamic Character These characters grow and change during the story for good or bad.
Static Character The opposite of the dynamic character. Static characters do not change but can add more tension or make a tense scene less so. While a major character can certainly remain static all the way through, much more often than not, the main character is dynamic.
Foil The foil is meant to have the exact opposite character traits from another character in the story to help bring more attention to the traits opposite hers. For example, the antagonist may be the foil for the protagonist, which helps to create more tension.
Flat Character The flat character is similar to a static character but has just a couple of traits that may be used for good—or not so good.
Round Character The round character is the opposite of the flat character. This character, like most people we know, has many different character traits, a mix of both good and bad ones.
Stock The stock character is a stereotype like the tough guy with a heart of gold, the overbearing Jewish mother, or the awkward nerd.