Cristina Yang is a fictional character from the television series Grey's Anatomy, created by Shonda Rhimes. She is portrayed by actress Sandra Oh and is known for her ambitious and competitive nature as a cardiothoracic surgeon. Cristina is a key character throughout the show's early seasons, showcasing her dedication to medicine and her complex relationships with other characters. Throughout the series, Cristina's character evolves, highlighting her struggles with personal and professional challenges. She is particularly close to her best friend, Meredith Grey, and their friendship is a central theme in the show. Cristina's journey reflects themes of resilience, ambition, and the pursuit of excellence in the medical field.