E-commerce platforms let organisations sell online: product catalogues, shopping baskets, checkout and payment integration, order handling, shipping, tax and customer accounts. They range from hosted shop services to open-source software on your own infrastructure, and are used by retailers, manufacturers selling directly and marketplaces. Shopify and Amazon's seller tools are well-known reference points.
A shop concentrates commercial dependencies. Customer and order data, product feeds, pricing history and traffic statistics sit in one system that also controls the checkout. A hosted platform can change fees, rules and available apps unilaterally, and an account suspension can stop your revenue overnight. Extensions, themes and payment modules usually follow the platform's own model, so moving means rebuilding the storefront even if the catalogue and customer list can be exported. Third-party scripts at checkout add further data flows.
When choosing a European option, ask where customer and order data are stored, which payment and logistics providers are involved, and whether European payment methods are supported. Check full export of products, orders, customers and redirects, the openness of the extension ecosystem, the ability to self-host or change host, and how the platform handles invoicing, VAT and consumer-law requirements in the countries you sell to.