This process is key to presenting a realistic character. Using the techniques developed by Stanislavski and others who followed him, actors make decisions about how their character will move and speak, what gestures and habits they might have and what they would wear. As part of their characterisation, actors develop a character profile to help them bring the character to life.
Characterisation may also be developed in relation to non-realistic characters. For example, in Shakespearean texts where a psychological view of character or Stanislavski’s method were unknown.
See Elements of Drama.