Logging is the practice of recording information about events, errors, and runtime behavior within an application. Logs help developers understand how a system behaves, diagnose issues, and monitor performance. Logs may include metadata such as timestamps, severity levels, request IDs, and contextual messages. Logging is essential for observability in distributed and cloud systems.
Why it matters
Without logs, troubleshooting becomes guesswork. Logging provides visibility into production systems, supports incident response, and enables audit trails. Proper logging design improves reliability and speeds up debugging.
Examples
Writing entries such as “User login failed” with a timestamp, or structured logs in JSON for ingestion into monitoring tools. Lessons like Basic Logging introduce logging techniques.