What is the main concept of a container in the Spring Framework?

In Spring Framework, the main concept of the container is the IoC (Inversion of Control) container, which manages the lifecycle and dependencies of objects (beans).

The container creates, configures, and links application objects, relieving developers from manually creating and wiring dependencies. This is achieved through configuration (annotations, XML, or Java config).

Example:

@Component
public class Service {
    // ...
}

@Component
public class Client {
    private final Service service;

    @Autowired
    public Client(Service service) {
        this.service = service;
    }
}

Here, Spring container creates Service and Client objects, automatically injecting Service into Client.

Thus, the container ensures dependency management and simplifies application architecture.