Social Mobility is –
Social mobility

Social mobility is the degree to which an individual's is family or group's social status can change throughout the course of their life through a system of social hierarchy or stratification.
The individual or family can move up or down the social classes based on achievements or factors beyond their control.
If such mobility involves a change in position, especially in occupation, but no change in social class, it is called "horizontal mobility". Example → a person who moves from a managerial position in one company to a similar position in another.
If the move involves a change in social class it is called "vertical mobility". Example → An industrial worker who becomes a wealthy businessman moves upward in the class system.
From rural to urban areas for work
Industrialization
Interaction between cultures
Movement in socio–economic stratas