Vertical mobility refers to the movement of an individual or a group up or down the hierarchy of positions within a society's social stratification system. This movement signifies a change in social class, status, or power relative to one's previous position or the position of one's family of origin. Upward mobility involves moving to a higher social stratum, often characterised by increased wealth, income, occupational prestige, or social status. Examples include obtaining a higher-paying job, achieving a higher level of education, or marrying into a wealthier family. Downward mobility, on the other hand, involves moving to a lower social stratum, which might occur due to job loss, business failure, or a decline in health or economic circumstances. Vertical mobility is a key aspect of social stratification and is often studied to understand the openness and fluidity of a society's social structure.