Zipkin is a distributed tracing system designed to help diagnose latency issues and track the flow of requests through complex systems. By collecting and visualizing trace data, Zipkin allows developers to identify performance bottlenecks and optimize system behavior. It captures timing data needed to troubleshoot latency problems in microservices architectures, providing visibility into how requests traverse various components in the system. Zipkin supports various data transports and integrates with multiple visualization tools, making it versatile for monitoring and improving system performance.