What is the role of the @Service annotation in Spring and why is it used?

The @Service annotation in Spring is used to denote a class as a service component of business logic. It is a specialized form of the @Component annotation, which allows Spring to automatically detect and register such classes in the application context through component scanning.

Using @Service helps to:

• Semantically distinguish application layers (e.g., controllers, services, repositories).
• Enable aspects (e.g., transactions) to be applied to business logic.
• Improve code readability by indicating that the class contains business logic.

Example:

@Service
public class UserService {
    public User findUserById(Long id) {
        // business logic
    }
}