This book provides an overview of what aid is, how it has changed over time and how it is practiced, as well as debates about whether aid works, for whom and what its future might be. The text shows how 'aid' is a contested and fluid concept that involves a wide and changing variety of policies, actors and impacts. It equips the reader with an understanding of what aid is, where it comes from and where it goes, how it is delivered and what its impacts are, and whether shortcomings are a result of a fundamental problem with aid, or merely the result of bad practices. It explores the changing political ideologies and conceptions of development that continually reshape how aid is defined, implemented and assessed, and how, despite a global commitment to the Sustainable Development Goals, we are at a point where the very notion of aid is being questioned and its future is uncertain. Each chapter includes case studies, chapter summaries, discussions, weblinks and further reading, to help strengthen the reader's understanding. Aid and Development provides an important resource for students, development workers and policy makers seeking an understanding of how aid works.