Azure Function Runtime is a specific version runtime where your Function App runs on top of it. Currently Azure function supports 3 versions of runtime host
- 1.x - Supports .NET Framework
- 2.x - Supports .NET Core2.1
- 3.x - supports .NET Core3.1
All 3 versions are supported for your production workloads. By default, Function Apps are created in 3.x version runtime. If you are using C# language to develop Azure functions and visual studio gives below options as function runtime while creating Function App
- Azure Functions V3(.NET Core)
- Azure Functions V2(.NET Core)
- Azure Functions V1(.NET Framework)
In order to find the function version number in your project, refer .csproj file.
1.x version setting in .csproj file
<TargetFramework>net461</TargetFramework>
<AzureFunctionsVersion>v1</AzureFunctionsVersion>
2.x version setting in .csproj file
<TargetFramework>netcoreapp2.1</TargetFramework>
<AzureFunctionsVersion>v2</AzureFunctionsVersion>
3.x version setting in .csproj file
<TargetFramework>netcoreapp2.1</TargetFramework>
<AzureFunctionsVersion>v2</AzureFunctionsVersion>
We are just referring C# as language, for other languages refer Azure Functions
documentation.