The Web page contains the resources (Pictures, JS, CSS, IFRAME, etc.) caused by the HTTP request basically from the same domain name, some sites for static resource files using a separate cookie-free domain name. Reduce the number of domain names in order to reduce the time required for domain name resolution, however, in some cases, the appropriate increase in the number of pages used in the page can improve the speed of the page.
"Maximum connections per Server", here is the server refers to the URL address of the domain name, not the server's IP address, so, the same IP, different domain names will be treated as different servers. The use of Apache Serveralias can easily add more than one alias domain name under the same domain name, the corresponding, in the domain name resolution only needs to be added an alias CNAME record.
Load limit of domain names when loading web pages