What is a round character in literature?

A round character in literature is one who has been fully developed (think three dimensional versus two-dimensional). They take on realistic identities and encompass complex characteristics.

A flat character, on the other hand, is one who has not been fully developed. He or she does not represent a fully realistic character, although physical characteristics might be explained.

Dynamic vs. Static characters are often paired with the above two. Dynamic characters are those who change and develop during the unfolding of the story. They learn something, undergo something, or make changes that represents their internal struggles and overcoming them.

A static character then, (which is usually represented by your flat character) does not undergo changes and remains the same, despite perhaps, having undergone some event.

The protagonist is your main character of the story (which is usually round).

The antagonist of the story is the opposition, set against the protagonist, which usually helps change the protagonist into a dynamic character.

So here's a recap (this is generally how it goes, but is not always set in stone):

Round - Dynamic - Protagonist.

Flat - Static - Anagonist. HELL YA DAWG!!!