Edward Deci and Richard Ryan’s self-determination theory (SDT) focuses on control versus autonomy as the differentiating factor between various forms of extrinsic motivation (activities that lead to a separable outcome) and intrinsic motivation (engaging in activities because they are enjoyable or interesting).
Extrinsic motivation refers to motivation that comes from outside an individual. The motivating factors are external, or outside, rewards such as money or grades. These rewards provide satisfaction and pleasure that the task itself may not provide. The most controlling form of extrinsic motivation is external regulation, which is performing a task to receive an external reward of avoid a punishment. A less controlling form of extrinsic motivation is introjected regulation, which is performing a task to avoid feelings of guilt or to affect one’s self-esteem or sense of self-worth.
Intrinsic motivation is defined as performing an action or behavior because you enjoy the activity itself. Whereas acting on extrinsic motivation is done for the sake of some external outcome, the inspiration for acting on intrinsic motivation can be found in the action itself. For example, you may read books simply because you enjoy reading.