Why does drupal commerce create an empty order for every anonymous user? Drupal Commmerce is creating an empty order for every single anonymous user in my website (over 13000 in just a few hours).

Users on my website have no direct access to the shopping basket, nor do they have any means of adding products to the cart, since for the moment, I'm only planning to use the Drupal Commerce functionality for specific users (i.e. I will create a product in the backend, then send the URL to the customer).

It doesn't seem right that so many orders are created for users who don't even have the shopping basket block in their page.

Why does this happen?

Is there a way to prevent it?

You can see in the screenshot how the empty-basket orders are being created for every anonymous user, this is slowing down the site!
There's nothing in core Drupal Commerce that would create an empty order for every anonymous session. Core Commerce will only create an order when an anonymous user adds a product to the shopping cart. This means some other module must be creating those orders for every session. I'd look to your contributed modules, especially if any are facilitating adding products to the cart via links instead of forms.