Characterization is the process of describing the physical and personality traits of a character.
Characterization is not much different in a short story than in a novel. The main difference is that in a short story there is not as much time to develop a character. A novel has more time to develop a character’s backstory and describe what he or she looks like and acts like, and then further show these through what the characters say and do. Short stories often focus on one character, and often the main purpose of the short story is to develop a character.
It is a way by which an author describes his/her charcater. This can be accomoplished by revelaing the cahracter's thoughts, thei appearance or simply speaking in the work.