The term 'Immobile Class' can be summarized as a CASTE system, which is a social hierarchy based on birth. It is a system of social stratification in which people are grouped into distinct classes, usually based on wealth, inherited social status, occupation, or race. The term 'CASTE' is derived from the Latin word castus, meaning 'PURE' or 'CHASTE'. This system has been used in many societies throughout history, and is still present in some parts of the world today.