Master Gichin Funakoshi developed 20 Precepts of Karate (Niju Kun) that act as a set of guidelines for karateka (karate practitioners). These precepts are heavily based on Bushido and Zen and ensure that the karateka are trained to be true budoka (practitioners of the warrior ways).
The precepts allude to teaching karateka compassion, respect, humility, awareness, patience, calmness, and more. These precepts are the foundation of Shotokan Karate but are also used in other styles of martial arts. The idea is, that coupled with your physical training, your mental state is what truly defines you not just as a martial artist, but as a person.