What’s the difference between NETStandard.Library package and Microsoft.NETCore.App packages?

Question

I wanted to know the difference between the two packages and if it had anything to do with .NETCore and NETStandard and compatibility. I found this:

The NETStandard target framework is an abstract target framework that represents API surface of many frameworks and platforms. As such NETStandard assemblies can run on any platform that supports the NETStandard targeted by that assembly, for example: .NET Desktop, Windows Phone, Universal Windows Platform applications, .NET Core applications, etc. NETCoreApplication is a concrete target framework that represents a single platform with both API surface and implementation. .NET Core applications are runnable on their own. .NETStandard libraries must be published-for or consumed-by a specific concrete target framework to be used in that type of application.

on https://masteringalm.github.io/framework/2018/07/24/NetStandardvsNetCoreApp-Project-Types.html But I'm not really sure how to use this to describe the differences between the two packages. I saw a post on this link: What's difference between.NetCoreApp and.NetStandard.Library? Where it said:

NetCoreApp is a platform and.NetStandard.Library is a library supposed to be cross platform (portable class library) for various .NET platforms runtimes.

I think this connects to differences between the two specific packages mentioned in the question header, but could anyone describe the differences between the packages in a not so convoluted way?

Answer 1

.net standard Each implementation of the managed framework has its own set of Base Class Libraries. The Base Class Library (BCL) contains classes such as exception handling, strings, XML, I/O, networking, and collections. .NET Standard is a specification for implementing the BCL. Since a .NET implementation is required to follow this standard, application developers will not have to worry about different versions of the BCL for each managed framework implementation. Framework Class Libraries (FCL) such as WPF, WCF, and ASP.NET are not part of the BCL, and therefore are not included in .NET Standard. The relationship between .NET Standard and a .NET implementation is the same as between the HTML specification and a browser. The second is an implementation of the first. Hence, the .NET Framework, Xamarin, and .NET Core each implement .NET Standard for the BCL in their managed framework. Since the computer industry will continue to introduce new hardware and operating systems, there will be new managed frameworks for .NET. This standard allows application developers to know that there will be a consistent set of APIs that they can rely on. Each .NET version has an associated version of the .NET Standard.

.NET Core is a free, cross-platform, open source implementation of the managed framework. It supports four types of applications: console, ASP.NET Core, cloud, and Universal Windows Platform (UWP). Windows Forms and Windows Presentation Foundation(WPF) are not part of .NET Core. Technically, .NET Core only supports console applications. ASP.NET Core and UWP are application models built on top of .NET Core. Unlike the .NET Framework, .NET Core is not considered a Windows component. Therefore, updates come as NuGet packages, not through Windows Update. Since the .NET Core runtime is installed App-Local, and applications are updated through the package manager, applications can be associated with a particular .NET Core version and be updated individually. For more information visit https://www.infoq.com/news/2017/10/dotnet-core-standard-difference/

Answer 2

Overly simplistic, but think of .NET Standard as a library that runs on any platform that can run .NET. This means it can run on Linux, Mac, Windows, etc. .NET Core is a minimalistic version of the "framework", so you can keep your your apps as small as possible and only add what you need. Core means only the core functionality that is absolutely required for an app to run.

Why is standard and core different? It is largely because the functionality of .NET on other platforms started open source with someone other than Microsoft. As such, the features have lagged behind .NET. The name of the .NET "framework" on other platforms was Mono. As some point .NET Core may well replace standard, but certain things have to get to the same level.

I imagine some purist will disagree with my oversimplification, but it is an easy way to get your head around the libraries.

As for what specifically is different between the two (or "what is missing from standard to be equivalent to core") - I am not sure. I am sure it can be looked up. In many cases, I have found Core works fine, such as dockerizing the application (Yeah, I made the word "dockerizing", but meaning running in a Docker container). The problems are when you run some package that cannot be handled in "Mono".

When it comes to packages you add into the standard or Core (Nuget anybody?), where there is a difference deals with one having features that cannot run in standard.