uri:universal Resource Identifier, generic resource identifier; url:uniform Resource Locator, Uniform Resource Locator; where the URL is a subset of the URI. the basic form of an address on the web is a URI, which represents the Uniform Resource identifier. There are two kinds of forms: URL: The most common form of URIs today is ubiquitous URLs or uniform resource locators. A URI is a simple string that identifies a resource in a uniform (standardized) way. Typically, this string begins with the scheme (the identifier of the namespace that names the URI-a set of related names), with the following syntax: [scheme:] Scheme-specific-part The URI begins with a scheme and a colon. Scheme starts with uppercase/lowercase letters, followed by empty or followed by more uppercase/lowercase letters, numbers, plus signs, minus and dot numbers. The colon separates scheme from Scheme-specific-part, and the syntax and semantics of scheme-specific-part (meaning) are determined by the namespace of the URI. As in the following example: HTTP://WWW.CNN shun Baidu. Avoid Baidu com, which HTTP is scheme,//www.cnn shun Baidu. Shun Baidu com is scheme-specific-part, And its scheme is separated from the scheme-specific-part by a colon. URIs have absolute and relative points, and absolute URIs refer to the URIs that begin with scheme (followed by a colon). The aforementioned http://www.cnn shun Baidu. com is an example of an absolute URI, other examples and mailto:[email protected] avoid Baidu Avajeff shun Baidu. com, news shun Baidu: Comp.lang shun Baidu. Java.help and Xyz://whatever. You can think of an absolute URI as referencing a resource in a way that is not dependent on the environment in which the identifier appears. If you use the file system as an analogy, an absolute URI is similar to the path of a file starting from the root directory. Unlike an absolute URI, a relative URI is not a URI that begins with scheme (followed by a colon). An example of this is articles/articles.html. You can think of a relative URI as referencing a resource in a way that relies on the environment in which the identifier appears. If the file system is used as an analogy, the relative URI is similar to the file path starting from the current directory. The URL is the abbreviation for Uniform Resource location, translated as "Uniform Resource Locator." In layman's words, URLs are strings used on the Internet to describe information resources, mainly used in various WWW client programs and server programs, especially the famous mosaic. URLs can be used in a unified format to describe various information resources, including files, server addresses and directories. at present, the biggest disadvantage is that when the information resource storage location changes, the URL must be changed accordingly. So people are looking at new ways of representing information resources, such as: URIs (Universal Resource Identifier) that is, "Common resource Identifiers", "Uniform Resource Names" and URC (Uniform Resource citation), which are "Uniform resource references" such as
URL and URI differences
