If you are using C# as a primary programming language then your project file extension is .csproj and if you are using VB as the primary language the .vbproj as a solution. In the previous version, if we want to modify our project solution file we need to unload the project then perform edit and then save and after this, we need to open this. But in this core, we no need to unload project and then edit you can directly do so. In the previous version whatever you add in your project the reference of this is added to the project file means .csproj file but in this new version or core no references are added in project files. 1) (Target Framework Moniker)TFM: To set the target framework we have to set in proj file and this is edit by showing below. This is TFM netcoreapp2.2. 2) AspNetCoreHostingModel : This is used for how the application is hosted which means InProcess or OutOfProcess. a) InProcess: In this host our asp app inside IIS worker process which uses w3wp.exe b) OutOfProcess: In this hosting model forward the web requests to backend Asp.net core app which is running on a KESTREL server. c) By default is InProcess hosting 3) Package Reference: It is used to include a reference for the Nuget package which is installed for our application. 4) Metapackage: Microsoft.AspNetCore.The app is used to manage or hold the list of dependencies. It is not added default references on its own but it holds the list of dependencies or other packages When we don’t specify the version the implicit version which is specified by SDK is taken.