title: .NET Standard and .NET Core 3.x or ASP.NET Core 3.x
body: <p>I have few questions on the .NET Standard and the recently announced .NET Core 3.0 and ASP.NET Core 3.1</p>
  
  <p>The previous versions of <a href="https://github.com/dotnet/standard/blob/master/docs/versions.md" rel="noreferrer">.NET Standard</a> had the same major version as that of the .NET core being released, but for .NET Core 3.1 the compatible is .NET Standard 2.1.</p>
  
  <p><a href="https://i.stack.imgur.com/whsbI.png" rel="noreferrer"><img src="https://i.stack.imgur.com/whsbI.png" alt="enter image description here"></a></p>
  
  <ol>
  <li>Is .NET Standard slowing going towards obsoletion or this is just a version number with no correlation to .NET Core release?</li>
  <li>Can we assume .NET Standard 2.1 will be compatible with  ASP.NET Core 3.1 as well ?</li>
  <li>If we migrate existing web apps and MVC web API to asp.net core 3.1 then what happens to the existing .net standard class libraries that were used by web app ?</li>
  </ol>
  
  <p>Do we change the target framework for our old .NET Standard class libraries from :</p>
  
  <pre><code>&lt;TargetFramework&gt;netstandard2.0&lt;/TargetFramework&gt;
  </code></pre>
  
  <p>To</p>
  
  <pre><code>&lt;TargetFramework&gt;netstandard2.1&lt;/TargetFramework&gt;
  </code></pre>
  
  <p>Or Change to</p>
  
  <pre><code>&lt;TargetFramework&gt;netcoreapp3.0&lt;/TargetFramework&gt; 
  </code></pre>
  
  <p>and add a FrameworkReference to Microsoft.AspNetCore.App</p>