What is "third-party carrier calculated shipping rates" or Shopify carrier service?

Third party carrier calculated shipping rates, also known as Shopify carrier service is a technology hosted by Shopify. Carrier service is available for Shopify's Shopify plans and above. Carrier service is the technology that allows third party apps like Packrooster Shipping to display dynamic shipping rates and pickup points at the checkout. If you want to display dynamic pickup points or custom shipping methods created in Packrooster Shipping at your checkout, you're going to need this in your Shopify store!