What are the levels of logging?

The main logging levels commonly used in systems and applications:

• DEBUG — detailed information useful for diagnostics and debugging.
• INFO — general information about the application's operation, important events.
• WARNING — warnings about potential issues that do not interfere with operation.
• ERROR — errors that affect execution but do not lead to application shutdown.
• CRITICAL (or FATAL) — serious errors leading to shutdown or critical failure.

Each level helps filter logs by importance and use them for monitoring and debugging. For example, in production, logs are often collected at WARNING level and above, while for development — DEBUG and above.