ARound characters are one-dimensional, often with a single character trait, while flat characters are more believable because they have a fuller personality with multiple character traits.
BFlat characters are physically flat, while round characters are physically round.
CFlat characters are major characters, while round characters are minor characters.
DFlat characters are one-dimensional, often with a single character trait, while round characters are more believable because they have a fuller personality with multiple character traits.