When developing on-line stores, you use Xperience as a content platform storing e-commerce data (SKUs, shipping carrier configurations, payment options, etc.) and develop the website as a separate live site application. The live site application interfaces with Xperience to retrieve data, perform price calculations, and utilize other e-commerce features the system offers.
Kentico Xperience 13 documentation and ASP.NET Core
Most documentation about running Xperience applications under ASP.NET Core can be found in a dedicated section: Developing Xperience applications using ASP.NET Core. The rest of the documentation still applies, but some code samples and scenarios might need slight modifications for Core projects.
Certain pages allow you to switch between Core and MVC 5 content using a selector located under the page heading.
All major differences between the MVC 5 and Core platforms are summarized in Migrating to ASP.NET Core.