Apple HealthKit is a software framework developed by Apple Inc. for iOS devices that allows health and wellness data to be collected, stored, and shared securely between different apps and with healthcare providers. It enables users to track and monitor their personal health metrics, such as steps taken, heart rate, sleep patterns, and more. HealthKit also enables developers to create health and fitness apps that can use this data to offer personalized insights and recommendations to their users. Additionally, HealthKit can be integrated with third-party medical devices, such as glucose meters and blood pressure monitors, to provide more comprehensive health tracking.