There are several theories of motivation that attempt to explain what drives human behavior:
1. Maslow's hierarchy of needs proposes that people are motivated to fulfill basic physiological needs first before pursuing higher-level needs such as esteem and self-actualization.
2. Expectancy theory suggests that motivation depends on the expectation that effort will lead to good performance and that performance will be rewarded. The more attractive the rewards, the stronger the motivation.
3. Equity theory states that people are motivated to maintain fair and equitable relationships with others where they perceive their inputs and outcomes to match those of others. Inequity can lead to actions to restore balance.