Site Reliability Engineering (SRE) is a set of principles and practices that incorporates aspects of software engineering and applies them to infrastructure and operations problems. SRE aims to create scalable and highly reliable software systems by bridging the gap between development and operations teams. Key principles of SRE include automation, monitoring, and proactive incident management. SRE teams focus on maintaining system availability, improving performance, and managing capacity. They use metrics and service level objectives (SLOs) to measure and ensure reliability. SRE practices help organizations achieve a balance between releasing new features and maintaining stable, reliable systems.