ASP.NET Core

ASP.NET Core is an open-source modular web-application framework. It is a redesign of ASP.NET that unites the previously separate ASP.NET MVC and ASP.NET Web API into a single programming model. Despite being a new framework, built on a new web stack, it does have a high degree of concept compatibility with ASP.NET. The ASP.NET Core framework supports side-by-side versioning so that different applications being developed on a single machine can target different versions of ASP.NET Core. This was not possible with previous versions of ASP.NET. ASP.NET Core initially ran on both the Windows-only .NET Framework and the cross-platform .NET. However, support for the .NET Framework was dropped beginning with ASP.Net Core 3.0.

Blazor is a recent (optional) component to support WebAssembly and since version 5.0, it has dropped support for some old web browsers. While current Microsoft Edge works, the legacy version of it, i.e. "Microsoft Edge Legacy" and Internet Explorer 11 was dropped when you use Blazor.