Get it All

Summary: High-level function that creates a new blog with the given parameters

Detail:  This function is a high-level function that combines a number of other functions to create a new blog.  It uses the install_blog(), install_blog_defaults() and add_user_to_blog() to set all the needed values in the database.  This would be the preferred function to use when creating a new blog, rather than all the lower-level functions.

Summary:  Creates an entry in the wp_blogs table (or equivalent) for a new blog with the domain $domain, the path $path and within the site $site_id.

Detail:  This is one of the functions called when a new blog is created.  It’s not the whole process, and unless you have a specific reason for calling it, is probably best left to itself.  It only really performs two functions, the first being the insertion of the new blog into the database, and the second being a refresh on the wp_cache to include the new blog.

NOTE: This function is deprecated in WordPress 3.0

Summary: Sets the text domain (language and country) of the given domain.

Detail: This function checks the locale set in Site Options and in the absence of this variable, defaults to en_US.  It then sets the path to the location of the language files to be used later.