There are six basic types of characters in literature.
The protagonist is the main character of a text. A protagonist is, therefore, the character the text follows throughout its entirety.
The antagonist is the character who conflicts with the protagonist. What this means is that the antagonist is the one who fights with the main character in the story.
A character can be one of the following: static, dynamic, flat, or round.
A static character is one which does not change over the course of the story. A static character, therefore, acts and thinks the same way in the beginning of the text as they do in the end.
A dynamic character, on the other hand, is a character who changes over the course of the text. A dynamic character will grow mentally or physically. Mental growth means that the character learns something and changes their perspective about the idea. Physical growth is simply that--the character grows physically.
A flat character is one who the author does not define (or describe) in detail. Little is known about a flat character.
A round character, on the other hand, is a character who is fully described by the author. This character is described both by their physical attributes and their mentality.