Spring supports three configuration approaches:

1. XML-based configuration: Traditional XML files
2. Annotation-based configuration: Using annotations like @Component, @Autowired
3. Java-based configuration: Using @Configuration classes

// Java-based configuration
@Configuration
public class AppConfig {
    @Bean
    public UserService userService() {
        return new UserService(userRepository());
    }
    
    @Bean
    public UserRepository userRepository() {
        return new UserRepository();
    }
}