This paper offers a description of and a contribution to a theory about the sector of out-of-school (non-formal) educational provision for young people. Focusing particularly on arts and culturally based activities, Julian Sefton-Green surveys the forms and structures of such provision and explores how it is used in a range of policy contexts, especially those aiming to redress social exclusion and promote economic regeneration. This is contextualised within a consideration of how out-of-school education could form part of the overall ecology of education provision offered to young people in the community. It draws on examples of study, research and evaluation from around the world. It is aimed at education administrators, academics, researchers, practitioners and social policy makers, and attempts to offer an overview of a crucial but neglected part of what should constitute the educational sector in the global, post-industrialised world.