Shopify is the biggest and most popular hosted eCommerce platform. It provides tools for all kinds of businesses to start selling fast without worrying about maintaining their website. A big marketplace of Shopify apps allows the store owner to add new functionalities that are not offered by the native platform to their stores.
One can use the Shopify theme to build their store & modify it easily using customization tools provided in the admin panel to match it to their brand. However, customization is possible only for pages up to the cart page. Checkout is standard for all Shopify stores and it can’t be modified in most of the stores.