There is no “aging”, but “aging”. Life histories and experiences related to advancement in age differ according to a variety of personal and social factors: gender, ethnicity, sexual orientation, socioeconomic status, citizenship skills, abilities and disabilities … Reflecting this plurality, the book brings together the scientific and clinical knowledge of 45 authors with professional trajectories and varied experiences. Together, they built a unique expertise about seniors and society, grouped into four broad sections: multiple aging and their representations, inequalities in the challenges faced, environments of the elderly and, finally, policies and actions Social enterprises.