UK universities are widely regarded as being among the best in the world. Maintaining the highest academic quality and standards is crucial to that reputation. This paper explains how universities ensure that students can have confidence that the time and money that they invest in their education are well spent. The UK model for assuring quality and standards in universities is sound and well-established. It is also well-respected internationally and has influenced parallel developments worldwide. It is a system which has evolved over time and which encourages universities to learn from experience, and each other, in seeking continuously to improve what they do. This paper describes how the quality assurance system works in all parts of the UK. It sets out the role of all the bodies involved, including the Quality Assurance Agency for Higher Education (QAA), and is intended to provide a clear explanation of how the different parts of the system fit together for anyone with an interest in how universities work. Annexed are: (1) Background to quality assurance in UK higher education: Recent history; (2) The Academic Infrastructure; and (3) UK differences. (Contains 31 notes.) [For summary report, "Quality and Standards in UK Universities: A Summary," see ED539764.]