As far as you need to be concerned as a .NET developer, you can freely interchange them as and when you feel like it.
Latest .NET Framework Classes Articles
Improved COM Interoperability in .NET 4.0
Learn about the COM Interoperability improvements coming with the .NET Framework 4.0 and how they will make your COM Interop such as Office applications much easier.
Creating Responsive .NET Applications with Microsoft Concurrency and Coordination Runtime (CCR)
Discover how CCR can work with the .NET Ping class APM functions.
An ADO.NET Data Services Tutorial
An ADO.NET Data Services Tutorial covering REST, querystring operations and expressions, HTTP verbs, Linq to Data Services, security, exceptions and tracing.
TIP: Closing your WCF Connections properly
This tip looks at properly closing a WCF connection from your application - whether you're using the proxy classes or a ChannelFactory.
New Features in Microsoft Visual Studio 2010 and the .NET Framework 4.0
Learn about several features relevant to developers in Visual Studio 2010 and the .NET Framework 4.0, such as parallel programming, XSLT debugging, new ASP.NET features, and new VB.NET and C# features that include the Chart control, XSD Designer, Lambda Expressions, and optional parameters.
Latest Developer Videos
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Comparing the stdio and iostream C++ Libraries
It's essential to know the differences in these libraries and use them correctly. This brief tutorial will guide you.

Ten Reasons to Look at .NET Core Now
The .NET Core is here now, and here are some reasons to begin using it.

Using Visual Basic to Create PDFs from Images
Explore how to convert images to a PDF document and how to combine two PDF documents into one.
The Value of APIs
Application Programming Interfaces (APIs) are where you have to be. It's not a matter of if as much as a matter of which.