Online shopping or online retailing is a form of electronic commerce which allows consumers to directly buy goods or services from a seller over the Internet using a web browser. Alternative names are: e-web-store, e-shop, e-store, Internet shop, web-shop, web-store, online store, online storefront and virtual store. Mobile commerce (or m-commerce) describes purchasing from an online retailer's mobile optimized online site or app.

According to the Wikipedia, A webstore is a website that sells products or services and typically has an online shopping cart associated with it. With the popularity of the Internet rapidly increasing, online shopping became advantageous for retail store owners, and many traditional “brick and mortar” stores saw value in opening webstore counterparts.
As explained by Wikipedia above, we can understand that an online store or webstore is more likely a real shop that we normally go to on weekend or anytime when we need to buy something.
And here is the Webstore characteristics according to Wikipedia as well.
Webstore Characteristics
Webstores typically share several similar characteristics, such as:
Sell Products or Services – Although some webstores are simply informational websites for the retail store or company they are associated with, most webstores do sell specific products or services.
Ecommerce Shopping Cart – The goal of most webstores is to have customers buy their products. These stores have an online shopping cart on their web site, and customers are able to add products to the shopping cart, enter their payment information, and check out.
Niche Industries – Many webstores target a specific industry and find their own unique corner of the market. However, exceptions include Amazon.com which found success in offering customers a myriad of products.