This release contains multiple SDKs. If you're using Visual Studio, look for the SDK that supports the version you're using. If you're not using Visual Studio, install the first SDK listed.

ASP.NET Core Runtime 3.1.8

The ASP.NET Core Runtime enables you to run existing web/server applications. On Windows, we recommended installing the Hosting Bundle, which includes the .NET Core Runtime and IIS support.

IIS runtime support (ASP.NET Core Module v2) 13.1.20234.8

Desktop Runtime 3.1.8

The Desktop Runtime enables you to run existing Windows desktop applications. This release includes the .NET Core Runtime, you do not need to install it separately.

Downloads for .NET Core 3.1 Desktop Runtime (v3.1.8) OS Installers Binaries Windows x64 | x86

.NET Core Runtime 3.1.8

The .NET Core Runtime contains just the components needed to run a console app. Typically, you'd also install either the ASP.NET Core Runtime or .NET Core Desktop Runtime.