When looking in the Solution Explorer in the Dependencies | NuGet section, you can see something very interesting, specific to ASP.NET Core 2.0 projects: the Microsoft.AspNetCore.All metapackage:
The Microsoft.AspNetCore.All project dependency was added automatically when you created your ASP.NET Core 2.0 Web Application. This is done by default for this type of project.
However, Microsoft.AspNetCore.All is not a standard NuGet package, since it does not contain any code or DLLs. Instead, it acts as a metapackage, referencing other packages it depends on. To be more specific, it includes all of the packages for ASP.NET Core and Entity Framework Core, together with their internal and external dependencies, and takes advantage of the .NET Core runtime store.
In the example, you can see that a wide variety of packages are retrieved...