Each [[web server]] runs [[HTTP]] server software, which responds to requests from Web[[Web_browser|web browsers]]. Generally, the HTTP server has a [[Directory_(computing)|directory (folder)]], which is designated as a document collection — files that can be sent to Web browsers connected to this server.<ref>[http://httpd.apache.org/docs/2.2/urlmapping.html Mapping URLs to Filesystem Locations Apache HTTP Server Version 2.2]</ref> For example, if the Web server has the ___domain name <code>example.com</code>, and its document collection is stored at <code>/usr/local/apache/htdocs</code> in the local file system, then the Web server will respond to a request for <code><nowiki>http://example.com/index.html</nowiki></code> by sending to the browser the (pre-written) file <code>/usr/local/apache/htdocs/index.html</code>.
For pages constructed on the fly, the server software may defer requests to separate programs and relay the results to the requesting client (usually, a web browser that displays the page to the end user). In the early days of the web, such programs were usually small and written in a scripting language; hence, they were known as ''scripts''.
