Book excerpt: This book explores the changing economics, regulations, and operations of electricity distribution networks. It highlights the central challenges and opportunities caused by the rise of decentralisation paradigm in the power system within this segment of the electricity supply chain. As decarbonisation objectives continue to transform the power sector, the distribution system experiences an increased penetration of energy and flexibility resources that come from a variety of sizes, technologies, and capabilities. This makes traditional approaches to economic, regulation and operation of electricity distribution networks obsolete. This book aims to provide insights into the ways which decarbonisation, decentralisation and digitalisation trends in the electricity sector will eventually shape future of distribution grids. It will be relevant to students, researchers, and policymakers interested in energy economics, the political economy of energy, and the electricity sector.