We often pay very less attention on the implementation of logging during the development phase of an application. On the other hand, it becomes mandatory when we deploy the application in production. Sometimes we just insert 'System.out.println' statements as a shortest path, which is a bad practice in the production level applications. Logging serves as a crucial tool for developers providing insights into the inner workings of an application. It also assists in diagnosing issues, and helping in the overall monitoring and maintenance of the software. In this article, we will learn logger in Spring Boot and related concepts with extensive amount of examples. What is a Log? In software development, "log" represents a report containing the history of events, activities, or messages