NSURL and NSURLHandle
URLs, Uniform Resource Locators, are the World Wide Web equivalent of a file system path. They specify where and what protocol to use to find a resource.
The canonical format that defines the pattern required for all URLs follows:
Each component of the URL format serves a specific purpose and helps identify the resource that is specified. For example, <scheme Component> is often http, https, file, or ftp and defines the protocol or communications scheme used to access a resource. The <authority_ Component> defines the computer that can provide the resource. The <authority_Component> is often an Internet domain name or IP address. The <path> ...