Static resources for Web sites why use separate domain names

In general, large sites will be static resources such as Js,css,logo pictures and other resources distributed deployment, and the use of independent domain name, namely static and dynamic separation. Distributed deployment can alleviate the load pressure on the application server, which is easy to understand, but why can I speed up the browser concurrent loading by using a separate domain name?

1, the browser to the same domain name of the number of concurrent connections limit (including two-level domain name), after the limit will be blocked.

2. When the browser requests a static resource from the server, it will first send the cookie under the same domain name, and the cookie will not be processed by the static resource server, wasting bandwidth

3, independent domain name convenient for us in the Agent service layer to do static and dynamic separation, dynamic separation is more conducive to CDN.

Static resources for Web sites why use separate domain names