some time back google get introduce this in terms of Jquery and all , now microsoft is also take a part on same while using ajax cdn. at first is service is free, does not require king of registration or anything ,and one thing is you can use it in both commercial and non-commercial purposes.
What does a CDN ?
How to use
now for example if you want to use jQuery from the Microsoft AJAX CDN you can simply add a standard script tag to your page, that you can put in you <Head > section
now whenever the script get required the browser get send the request to the microsoft cdn for functiuon and from there automatically updation get happen
one better advantage is it get cache automatically so no need to send request and make http page heavier. so from the SEO (search engine optimization ) point of view also its too good .
now how you can use that on Visual Studio on your application,
now a days The ASP.NET 4.0
that means script get generate automatically so no need of write a code for same , this again useful for SEO purpose for JS minfication . this problem get solve ones you check you application in terms of Google page speed issue.
you need to simply set EnableCDn="true" automatically it get work look at below how exactly it get work
now hope u got the idea clear how exatly it get work and how its useful
thanx , if u want more on same plz add a comment on this post