What does the @SpringBootApplication annotation do? @SpringBootApplication एनोटेशन क्या करता है?

@SpringBootApplication is a convenience meta-annotation that combines three annotations: @Configuration, which marks the class as a source of bean definitions; @EnableAutoConfiguration, which triggers auto-configuration; and @ComponentScan, which scans the current package and sub-packages for Spring-managed components.

Placing it on the main class means a single annotation sets up configuration, auto-configuration, and component scanning together, which is why the main application class is conventionally placed in the root package.

@SpringBootApplication
// equivalent to:
// @Configuration
// @EnableAutoConfiguration
// @ComponentScan
public class DemoApplication { }