개념) [DI/IoC](<https://tecoble.techcourse.co.kr/post/2020-07-18-di-constuctor-injection/>)

1) [@Bean(@Configufation), @Component](https://jojoldu.tistory.com/27)

2) @ComponentScan

3) [@SpringBootApplication](<https://tecoble.techcourse.co.kr/post/2021-10-14-springboot-autoconfiguration/>)