Language Control is a companion extension to the Publisher module. It lets you easily define sub-domains to be used for each language of your site.
This extension does not create sub-domains on your server. You must setup the virtual hosts entries yourself in your Apache config file, or via CPanel or another web based server administration tool.
Once a domain name/url are defined for each language in the extension settings they will be referenced when the site loads to determine the language for the user. Several Publisher settings, such as Detect Language from Browser are turned off. Using this extension forces the assigned language to the domain.