Tracing is a debugging technique used to capture debugging data that visualizes operation flows, such as a page load. A trace consists of spans with start and end times and arbitrary data attached to them. To get started with capturing traces, one needs to install the Sentry React SDK, initialize it at the top of the app, and deploy changes. The SDK automatically instruments the majority of the codebase, allowing for immediate inspection of tracing data. Tracing can help identify performance issues like fetch waterfalls, where multiple fetch requests are invoked in a sequential manner, leading to significant performance degradation. Identifying these waterfalls involves inspecting slower page loads, which may reveal a fetch waterfall that can be optimized to improve page load times.