What is the role of Data Transfer Object in the process of data exchange between application layers?

Data Transfer Object (DTO) is a simple object used for transferring data between application layers, such as between data access layer and business logic or between server and client.

Role of DTO:

• Encapsulate data without business logic.
• Simplify data transfer, especially when working with remote calls or serialization.
• Reduce coupling between layers, as DTO does not depend on internal layer implementations.

Example of DTO in PHP:

class UserDTO {
    public string $name;
    public string $email;

    public function __construct(string $name, string $email) {
        $this->name = $name;
        $this->email = $email;
    }
}

This object can be used to transfer user data between layers without transferring the entire model with business logic.