Spring Core: IoC and Dependency Injection

Explain Inversion of Control (IoC) and the Dependency Inversion Principle.

Describe the role of the Spring IoC container and the ApplicationContext.

Define Spring beans using component scanning (@Component, @Service, @Repository).

Inject dependencies using constructor injection with @Autowired.

Use @Configuration and @Bean to define beans explicitly in a configuration class.

Use @Qualifier to resolve ambiguity when multiple beans implement the same interface.