System.Web.Optimization vs Microsoft.Web.Optimization

Those namespaces are somehow related to each other, but I do not understand the difference and when I need the one or the other?!

Can anyone please explain that to me?

What is System web Optimization?

The System. Web. Optimization namespace includes classes that support Content Delivery Networks (CDN) and the process of optimizing JavaScript and cascading style sheet (CSS) files in a website to reduce file size and improve page performance.

What is Microsoft AspNet web optimization?

The ASP.NET Web Optimization Framework was introduced by Microsoft for optimizing the ASP.NET web application performance. In order to optimize web application, this framework uses the following two techniques: By reducing the number of requests to server. By reducing the size of requested resources.

Microsoft.Web.Optimization namespace has been replaced with System.Web.Optimization in 1.0.0-beta version of the Microsoft.Web.Optimization package. The System.Web.Optimization namespace is going to be included in System.Web.dll for .NET 4.5 Framework release (according to preview documentation).