This book provides a detailed guide to the highly specialised but little known health information workforce -  people who are health informaticians, digital health experts, and managers of health data, health information and health knowledge.  It explains the basis of their unique functions within healthcare   their educational pathways and standards, professional qualifications and industry certifications, scholarly foundations and principles of good practice. It explores their challenges, including the rise of the health consumer movement, the drive to improve equity and quality in healthcare, new technologies such as artificial intelligence, and the COVID-19 infodemic. Case studies describe how practitioners in real-world roles around the world are addressing the digital transformation of health.