Put simply, the dp.shop is a website that is a... shop. We design a website for you - either a custom design built to your requirements, one of our pre-built templates or a design supplied by you. The shop functionality is then plugged into that website.
So you know what Amazon does? That's pretty much what your website will do. People come to your site, add items to their shopping basket, register or login, checkout and pay. They can then view their order history, see recommended products based on their purchase history, add items to a wishlist and do pretty much all the things they can do on Amazon. You have a control panel where you can add products, manage stock, process orders, discounts, shipping rates and control so many settings that, even as the developer, I can't remember them all.