Extrinsic motivation is a reward or inducement provided by an external person or entity to compel a person to act. Companies typically use pay structures, public praise and employee awards as extrinsic motivators to encourage employees to perform at optimum levels.
An extrinsic motivator is often needed when a person isn't motivated intrinsically or by a personal desire to achieve a goal or complete a task. In school, grades are an extrinsic motivator. Some students are as motivated to achieve a quality grade as they are to learn. Extrinsic and intrinsic motivation can coexist. Someone may be extrinsically rewarded with high pay for a job but also truly enjoy the work.