This book is written for people working in primary care, who want to understand more about how they contribute to improving the health and health care of the populations that they serve, and for people working in public health, who want to understand the essential contribution of primary care to improving health. It sets out the nature, purpose and relevance of public health approaches to primary care practitioners and primary care organisations.Primary care teams have had a long established role in public health, providing preventive services to populations, through the registered population in general practice. This model of a registered practice population has withstood multiple reconfigurations and reorganisations within the NHS and is the envy of many countries trying to create a public health system with primary care at its heart. There are clear differences in approach, with the inevitable conflicts between the rights of the individual set against the responsibility to ensure services are delivered fairly and equitably to whole populations. This book explores this dilemma, showing how people working in primary care can cross the divide to become part of the public health system, and in doing so are well placed to make a difference to the health of their populations.