A character study is a literary device that involves creating an in-depth analysis and portrayal of one or more characters in a story. It provides detailed information about their personality, motivations, behaviors, thoughts, feelings, and actions to help readers better understand them as individuals. A character study can also reveal the psychological makeup of a character by examining their backgrounds, upbringings, experiences, and relationships with others. This technique helps writers create more realistic characters that are relatable and engaging for readers, while providing deeper insights into the story's themes and messages.