This document summarizes several theories of work motivation. It discusses Maslow's hierarchy of needs theory, McGregor's Theory X and Theory Y about employee motivation, Alderfer's ERG theory modifying Maslow's needs, McClelland's acquired needs theory about affiliation, power and achievement, Herzberg's two-factor theory about motivators and hygiene factors, and process theories like Vroom's expectancy theory, Locke's goal-setting theory, and Adams' equity theory. It also discusses the importance of equitable rewards in motivating employees.