Social mobility is defined as the movement of individuals, families, households, or other categories of people within or between layers or tiers in an open system of social stratification. Open stratification systems are those in which at least some value is given to achieved status characteristics in a society. The movement can be in a downward or upward direction.Absolute social mobility refers to the overall numbers of people who end up in a different layer of stratification from that of their parents. Relative social mobility refers to the differences in probability of attaining a certain outcome, regardless of overall structural changes; a society can have high absolute mobility and low relative mobility. The availability of at least some social mobility can be important in providing pathways to greater equality in societies with high social inequality.