Final answer:
Social mobility refers to individuals changing positions within a social stratification system, including upward and downward mobility in socioeconomic class.
Step-by-step explanation:
Social mobility refers to the ability of individuals to change positions within a social stratification system. When people improve or diminish their economic status in a way that affects social class, they experience social mobility. Individuals can experience upward or downward social mobility for a variety of reasons. Upward mobility refers to an increase when they move from a lower to a higher socioeconomical class, while downward mobility occurs when they move from a higher to a lower socioeconomic class.