RUM (Real User Monitoring) and APM (Application Performance Monitoring) are complementary tools that provide a comprehensive view of web applications from both the user's perspective and the service layer's perspective, forming part of an Intelligent Observability platform. RUM focuses on real-time user experience by monitoring metrics such as page load times, errors, and user engagement through browser-embedded data, offering insights that help optimize user interfaces and improve customer retention. APM, on the other hand, monitors the performance of software applications throughout their lifecycle, including metrics like latency and error rates, to ensure applications meet performance goals, enabling technical teams to identify and resolve issues proactively. Together, these tools provide full-stack observability, offering businesses detailed insights into both system operations and user experiences, which are critical for optimizing performance and enhancing business outcomes across various industries, from e-commerce to financial services and media delivery.