Standards play a simultaneously central and unsung role in our modern world. From the first attempts to unify weights and measures in ancient empires to today's complex web of international protocols governing everything from the internet to food safety, standards have been the bedrock upon which societies build their economic, political, and social structures. But who sets standards, and why does that matter? And what roles do standards play in the progress of nations? Because development is about improving standards of living, 'World Development Report 2025' argues that setting and enforcing standards across the economy, society, environment, and government are the heart of the development process. The Report will explore how voluntary and mandatory standards can be used as a tool for development--to improve the productivity of firms, enable job creation, conduct mutually beneficial trade, enhance public access to basic social services, widen financial inclusion, and limit the adverse impacts of economic activities on the environment--and thereby quicken progress towards the sustainable development goals.