In this video, I break down logging in Spring Boot the right way—what it actually is, why you need it, and how it helps you when your app works locally but fails in production. I explain logging as “how your application talks to you” and why, without logs, you’re basically flying blind. We look at the Spring Boot logging defaults, the out-of-the-box console output, and what that default log format contains (timestamp, level, PID, thread, logger name, and the message). Then I take everything hands-on with a simple controller and show you how to create logs using SLF4J (Simple Logging Facade for Java). I demonstrate parameterized logging, and I explain logging levels (trace, debug, info, warn, error, and off) and how Spring Boot filters them by default. After that, we configure logging.level.root in application.properties to enable trace/debug when needed. Finally, I show practical customizations: changing the console log pattern, writing logs to a file using logging.file.name, and customizing the file pattern separately—so you can capture logs in production and debug issues without guesswork.