In 1.0, ASP.NET Core itself is a "package" and appears in the project just like any other NuGet package reference. This has its advantages and disadvantages. Over time, this model has evolved. In 2.1, ASP.NET Core eventually evolved into a "shared framework" for .NET Core. And ASP.NET Core 3.0 continues to change in this direction -Some subcomponents will be removed from the ASP.NET Core shared framework in 3.0:
Entity Framework Core (Microsoft.EntityFrameworkCore.*)
As the .NET Framework will gain less new platform and language features from .NET Core in the future, and because of the .NET Framework's update strategy, this will impact existing applications. To ensure that ASP.NET Core can take advantage of improvements in .NET Core, starting with 3.0,ASP.NET Core will only support running on .NET Core, still using ASP.NET Core on the .NET FrameworkDevelopmentYou can continue to get full support with the 2.1 LTS version.MicrosoftSupport for 2.1 will continue until 2021.
About ASP.NET Core 3.0 only supports projects running on .NET Core, and senior software engineers for ASP.NET Core projects have released a release on GitHub.Public issueProvide a channel for discussion.
A detailed change plan for ASP.NET Core 3.0,Please check the official blog announcement.