A URL parser is a software tool, or library used to break down a Uniform Resource Locator (URL) into its constituent parts such as the scheme (e.g. "http"), hostname (e.g. "www.example.com"), port (e.g. "80"), path (e.g. "/path"), query string (e.g. "query=value"), and fragment identifier (e.g. "#fragment"). The purpose of a URL parser is to help applications process and programmatically manipulate URLs.