example.php

// Coupled to framework (a service knowing about the implementation of the data layer)
class OrderService
{
  public function getOrders(): iterable
  {
    return Order::all();
  }
}

// Not coupled to framework 
// first an interface
interface OrderRepository
{
  public function all(): iterable;
}

// then the concrete implementation
final class EloquentOrderRepository implements OrderRepository
{
  public function all(): iterable
  {
    return Order::all();
  }
}

// And then, use that interface in the service
class OrderService
{
  public function __construct(
    private readonly OrderRepository $orderRepository
  )

  public function getOrders(): iterable
  {
    return $this->orderRepository->all();
  }
}