There are more Wi-Fi devices than humans. From cafe culture to home automation, remote community networks to smart cities, Wi-Fi is an invisible but fundamental element of contemporary life. Loosely regulated, low-cost, and largely overlooked by researchers, this hugely successful technology has driven the rise of the smartphone and broadband internet and is a vital element in the internet of things and the next wave of automation. Thomas, Wilken and Rennie provide the first accessible, comprehensive account of Wi-Fi and its social and cultural consequences. Identifying the Wi-Fi networks in our homes, cities and communities, the authors describes how Wi-Fi has changed - and continues to shape - everyday places and spaces. They discuss Wi-Fi's origins as an experimental technology at the end of the last millennium, the conflicts generated around its ownership and control, and the ideas and expectations attached to it by technologists, futurists, activists, and entrepreneurs. The authors reveal the ways in which Wi-Fi is an inherently social and political technology, animated by conflicting aspirations for local, public, and community control, and defined by private and corporate interests. Wi-Fi has extended and intensified our online lives as well as promising a more inclusive internet. Wi-Fi is essential reading for students and scholars of media and communication, as well as anyone who wants to better understand this ubiquitous and influential technology.