Steak doneness refers to the level of cooking a steak has reached, which affects its flavor, texture, and juiciness. The most common levels of doneness are rare, medium rare, medium, medium well, and well done. Each level is determined by the internal temperature of the steak, with rare being around 125°F and well done reaching about 160°F or higher. Cooking a steak to the desired doneness often depends on personal preference. Medium rare is popular for its balance of tenderness and flavor, while well done is preferred by those who like their meat fully cooked. Understanding these levels helps in achieving the perfect steak experience.