A marketplace is a platform where vendors can come together to sell their products or services to a curated customer base. The role of a marketplace owner is to bring together the right vendors and the right customers to drive sales through an exceptional multi-vendor platform - sellers have a place to gain visibility and sell their products, and the marketplace owner earns a commission from each sale. An online store, on the other hand, is a single store selling its own products online. All marketing and operations are managed by the company that owns the website and products.
Marketplace owners do not own the inventory their platform sells, unlike online store owners. The marketplace owner, therefore, leaves the more operational side of the business to vendors while focusing mainly on promoting their marketplace brand with a view to driving traffic to the platform and converting site views into sales.
Examples for marketplaces are large companies with huge inventories like Amazon, Rakuten or eBay or niche platforms like Etsy (handmade crafts), Runnics (sportswear for running) or Shop. Surf (Surf & Skate gear and fashion). In contrast, an online store is just one single company, such as Zara, Apple or Nike, selling its own products online via its own online shop.