Spring Boot's ability to create self-contained JAR files that can run directly is one of the many reasons it has become a favorite framework for Java developers. This unique feature eliminates the need for complex server configurations, making deployment smoother and faster. But how does this work under the hood? What makes a Spring Boot JAR so different from a traditional Java JAR? This article will unravel these questions, showing you not only why Spring Boot JARs can run directly but also the steps behind their execution.