Characterization is the process through which an author reveals a character's personality. It's a gentle unfolding of a woman's confidence or a man's brilliant mind.
We see this in plays, novels, TV shows, movies, poems, and any other format that involves the creation of a character. Examples of characterization come forth in a character's thoughts, words, deeds, appearance, and more.
“Mr. Bingley was good-looking and gentlemanlike; he had a pleasant countenance, and easy, unaffected manners.”
“Everybody knew Bagheera, and nobody cared to cross his path, for he was as cunning as Tabaqui, as bold as the wild buffalo, and as reckless as the wounded elephant.”