The iOS Human Interface Guidelines are a set of recommendations created by Apple to help developers design user-friendly applications for the iOS platform. These guidelines cover various aspects of app design, including layout, navigation, and visual elements, ensuring a consistent and intuitive user experience across all iOS apps. By following these guidelines, developers can create applications that not only look good but also function well on iPhones and iPads. The guidelines emphasize the importance of usability, accessibility, and responsiveness, helping to enhance user satisfaction and engagement with the app.