This document defines and discusses different types of social mobility, including horizontal, vertical, upward, downward, inter-generational, and intra-generational mobility. It notes that social mobility refers to shifts in social status that can be higher, lower, between generations, or within a generation. The document also outlines causes of social mobility like education, caste, and occupation, as well as importance like providing opportunities and acting as a safety valve in societies. However, it mentions costs like rising expectations and requiring geographic mobility.