When you create a marketplace site, you should remember that both e-Commerce sites are a marketplace and an online shop, but functionality varies.
An online store is a retail store with a specific domain name, a single store that sells items from one seller. Shopify, Magento, BigCommerce, and others are platforms for creating online stores on everyone's A-list. Individual online stores can be large, with hundreds of positions and just one or two brands of small retail items.
A marketplace is a two-sided platform for electronic commerce; indeed, it is a website for the market, a meeting point for many buyers and many sellers where they interact and make regular deals via one website. It can be a mobile app (Uber) or a website (AliExpress). In the case of the marketplace, between those who sell and those who purchase goods or services, the platform on its own is a mediator. Buyers may pick items from multiple retailers and buy them on a single website or app, such as Amazon.