Manuel Castells is a sociologist especially associated with information society and communications research.
His work synthesises empirical research literature with combinations of urban sociology, organization studies, internet studies, social movements, sociology of culture, and political economy. About the origins of the network society, he posits that changes to the network form of enterprise predate the electronic internet technologies (usually) associated with network organisation forms (cf. Castells and Organization Theory). Moreover, he coined the (academic) term "The Fourth World", denoting the sub-population(s) socially excluded from the global society; usual usage denotes the nomadic, pastoral, and hunter-gatherer ways of life beyond the contemporary industrial society norm.
He is the author of 22 academic books and editor or co-author of 21 additional books, as well as over 100 articles in academic journals. His trilogy "The Information Age: Economy, Society, and Culture" was published by Blackwell in 1996-98 in the first edition and in 2000-2003 in its second edition.