CSS directly to the page and external call difference

CSS tutorials are placed directly on the page and external calls differ
1. Reduce HTTP Requests
Linking to the outside inevitably adds additional HTTP requests, which is time-consuming.
2, to avoid the bare page
If the server that holds the CSS hangs, the entire front page hangs off. On the page, more secure. When a user accesses a page, it does not cause a bare page because the CSS does not load.
3. About modification
You may say this is not easy to modify and manage.
In fact, generally are loaded with the program dynamic, and then use the cache static home and so on.
That's all I know for the time being.

4, put the surface to facilitate the external modification, but if the CSS loading does not come in, may result in the bare page

General large flow of the site are the CSS directly on the page, which is to cope with a large flow of an optimization scheme, such as NetEase home, Tencent home and so on.