Many Spring Boot developers like their apps to use auto-configuration, component scan, and be able to define extra configuration on their “application class”. A single @SpringBootApplication annotation can be used to enable those three features, that is:

@EnableAutoConfiguration: enable Spring Boot’s auto-configuration mechanism

@ComponentScan: enable @Component scan on the package where the application is located (see the best practices)

@Configuration: allow to register extra beans in the context or import additional configuration classes

The @SpringBootApplication annotation is equivalent to using @Configuration, @EnableAutoConfiguration, and @ComponentScan with their default attributes,