when you change your social classs or strata, it is called social mobility
   Movement in the socio-economic ladder.
   May occur in two ways: Vertically and Horizontally.
   Types are:
   1. Intergenerational Mobility: When social status of two generations are compared.
   a. Upward Intergenerational: If a person can earn a better social class/status compared to
    his/her parents’ social class/status, then that is referred as Upward Intergenerational mobility.
   b. Downward Intergenerational: If a person’s parents have a better social class/status
    compared to that person’s own social class/status, then that is referred as Downward
    Intergenerational mobility.
    c. Horizontal Intergenerational: If a person has earned the same social class/status compared
    to his/her parents’ social class/status, then that is referred as Horizontal Intergenerational
    mobility.
   2. Intra-generational Mobility: When social status within one generation is compared.
   a. Upward Intra-generational mobility: If a person’s present social class/status is better than
    his/her previous social class/status, then that is referred as Upward Intra-generational
    mobility.
    b. Downward Intra-generational mobility: If a person’s present social class/status is less than
    his/her previous social class/status, then that is referred as Downward Intra-generational
    mobility.
   c. Horizontal Intra-generational mobility: If a person’s present social class/status is identical to
    his/her previous social class/status, then that is referred as Horizontal Intra-generational
    mobility.
   3. Structural/Stratum Mobility: An entire social class/group will experience this mobility
    together due to a major change that may occur in the social structure.
   a. Upward Structural/Stratum Mobility: Social/status of an entire social class/group will get
    elevated compared to other classes/groups of the society due to a major change that may
    occur in the social structure.
   b. Downward Structural/Stratum Mobility: Social/status of an entire social class/group will get
    demoted compared to other classes/groups of the society due to a major change that may
    occur in the social structure.
    c. Horizontal Structural/Stratum Mobility: If there is no impact on the social/status of an
    entire social class/group due to a major change that may occur in the social structure, the that
    is referred as Horizontal Structural/Stratum Mobility.
   4. Exchange Mobility: This is a result of almost equal number of people
    experiencing upward and downward mobility at the same time in the
    same society keeping the social structure stagnant.
   All societies can be categorized in to two types ---
   1. Open Class System Society: If in a society, opportunities and scopes
    are open to the people with which they may bring change to their own
    social class/status, then that society is known as Open Class System
    society. Social statuses of the people are known as Achieved status in
    that society.
   2. Closed Class System Society: If in a society, opportunities and scopes
    are closed to the people with which they may bring change to their own
    social class/status, then that society is known as Closed Class System
    society. Social statuses of the people are known as Ascribed status over
    which they do not have any control.