This lecture explores the concept of mobility in urban areas, emphasizing its dependence on the opportunities provided by the context and the abilities of individuals. It discusses three approaches to understanding mobility as a social, spatial, and temporal phenomenon, as well as the interplay between motility, movements, and access. The bidimensional nature of motility is examined, highlighting its potential to address inequalities and diversity in lifestyle choices. Additionally, empirical explorations on the reversibility of mobility are presented, focusing on the nature of change from one state to another. Overall, the lecture delves into the intricate relationship between mobility and urban planning.