Self-determination theory (SDT) is a theory of human motivation that examines how social contexts and individual differences influence different types of motivation. SDT proposes that people have three basic psychological needs - competence, autonomy, and relatedness - and that satisfying these needs promotes autonomous motivation and intrinsic aspirations, which facilitate well-being and engagement. SDT distinguishes between autonomous motivation, which involves willingness and choice, and controlled motivation, which involves pressure and obligation. The theory also examines factors that promote internalization and integration of extrinsic motivation to become more autonomous.