In computer terminology, a Uniform Resource identifier (Uniform Resource Identifier, or URI) is a string that identifies the name of an Internet resource. This type of identification allows users to interact with resources in the network (generally referred to as the World Wide Web) through specific protocols. The URI is defined by a scheme that includes a determination of syntax and related protocols. Each resource available on the Web-html documents, images, video clips, programs, and so on-is located by a generic resource identifier (Uniform Resource Identifier, referred to as the "URI").composition Edit URIs are generally made up of three parts:
First,Host name.
Storage of resourcesThe name of itself, represented by the path. Refer to the following URI, which conforms to the current RFC4395 specification: protocol name://domain name. root domain/directory/filename. suffixes such as http://b.c/d/e.f (Assuming that B.C is an available domain name, E.F is a standard file) This URI is this: a resource that can be accessed through the HTTP protocol, located on the host B.C, accessing the "D" folder on the host through the string "/d" in the URI and accessing the host via "E.F" request "/d/ E.f "This file. This is another example of a URI that points to a user's mailbox: mailto: name @ domain NOTE: Most readers may be familiar with "URLs" rather than URIs. A URL is a subset of the URI naming mechanism.
second, the markerSome URIs point to the inside of a resource. This URI ends with a "#" and follows a anchor glyph (called a fragment marker). For example, here is a URI that points to section_2: protocol://domain/directory/File # fragment identifier (for example:/a/b.php#a)
third, relative URIThe relative URI does not contain any naming specification information. Its path usually refers to resources on the same machine. Relative URIs may contain relative paths (for example, "..") Represents the previous layer path) and may also contain fragment markers. To illustrate the relative URI, let's say we have a basic URI: protocol://The domain name/directory \ \ \ file C uses the relative URI in the following link:. /file D It expands into full URI is "protocol://domain/directory/file D", below is an image of the relative uri: It expands into full URI is "protocol://Domain/directory A/icons/logo.gif". In HTML, URIs are used to: link to another document or resource (see A and link elements). Link to an external style sheet or script (see link and scripting elements). Include images, objects, or applets within the page (see image, Object, applet, and input elements). Create an image map (see map and area elements). Submit a form (see form). Create a framework document (see Frame and IFRAME elements). Refer to an external reference (see Q, Blockquote,ins, and Del elements). Point to a metadata that describes the document (see Head Element).2 using editing The URL is an abbreviation for uniform Resource Locator, translated as "Uniform Resource Locator." The format of the ◇url format URL is composed of the following three parts: the first part is the protocol (or service mode); The second part is the host IP address (and sometimes the port number) where the resource is stored, and the third part is the specific address of the host resource. , such as directory and file name. The first and second sections are separated by a "://" Symbol, and the second and third sections are separated by a "/" symbol. The first part and the second part are indispensable, and the third part can be omitted sometimes. ◇url the URL of the sample file: When a file is represented by a URL, the server is represented by a filename, followed by information such as the host IP address, the file's access path (that is, the directory), and file name. Directories and file names can sometimes be omitted, but the "/" symbol cannot be omitted. Example: File://a:1234/b/c/d.txt represents the acquisition of resources using the FTP protocol, the resource target is a host of the 1234 port of the B directory under the C directory under the D.txt. The URL of HTTP has been demonstrated in the composition of the URI and is no longer stated here.3 Difference Editions URI, URL, and Urnuri:uniform Resource Identifier, Uniform Resource Identifier, Url:uniform Resource Locator, Uniform Resource Locator, Urn:uniform Resource Name, The Uniform Resource name. which
Url,urn is a subset of URIs。 The basic form of an address on the web is a URI, which represents the Uniform Resource identifier. There are two forms: URLs: The most common form of URIs today is ubiquitous URLs or uniform resource locators. An updated form of Urn:url, the Uniform Resource name (URN, Uniform Resource name) is not dependent on the location, and it is possible to reduce the number of failed connections. But its popularity will take time, because it requires more sophisticated software support. A URI is a simple string that identifies a resource in a uniform (standardized) way. Typically, this string begins with scheme (the identifier of the namespace that names the URI-a set of related names), with the following syntax: [scheme:] Scheme-specific-parturi 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 the following example:/HTTP domain, where HTTP is the scheme,//domain name is Scheme-specific-part, and its scheme is separated from 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 http://Domain name mentioned earlier is an example of an absolute URI, and other examples include mailto:[email protected], news address, 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 a variety of lettersResources, including files, server addresses, directories, and so on. 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 to represent information resources, such as URIs (Universal Resource Identifier), which are "Generic resource Identifiers" (see RFC 1630), URN (Uniform Resource name), and Uniform Resource name and URC (Uniform Resource citation) are "Uniform resource references" and so on. The URI is still in the further study. The direction of research is to compensate for the disadvantages of URLs.4 with urn editor A URI can be considered a locator (URL), a name (URN), or both. A Uniform Resource name (URN) is like the name of a person, whereas a Uniform Resource Locator (URL) represents a person's address. In other words, the urn defines the identity of something, and the URL provides a way to find it. Urns are used only for naming purposes, not for specifying addresses. The ISBN system used to identify a unique bibliography is a typical URN usage example. For example, ISBN 0486275574 (urn:isbn:0-486-27557-4) does not have the ambiguity to identify a particular version of Shakespeare's play Romeo and Juliet. To get the resource and read the book, people need its location, which is a URL address. In a Unix-like operating system, a typical URL address might be a file directory, such as File:///home/username/RomeoAndJuliet.pdf. The URL identifies the ebook file stored on the local hard drive. As a result, URLs and urns complement each other.technical point of viewA URL is a URI that identifies an Internet resource and specifies the method on which the resource is to be manipulated or obtained. may be identified by a description of the primary means of access, or by a network "location". For example, a URL that identifies a specific resource (home page) and represents some form of the resource (for example, the HTML code for the first page, as encoded characters) is available through the web host specified by the URL. A urn is a URI that specifies a resource by name based on a namespace. A urn can be used to point out a resource without pointing out its location and how it is obtained. Resources do not need to be Internet-based. For example, URN urn:isbn:0-395-36341-1 specifies the URI that identifies the system (That is, ISBN ISBN) and the unique representation of a resource in the system. It allows people to talk about the book without pointing out its location and how to get it. Technical publications, especially those published by the IETF and the publishers, basically no longer use the term "url," because there is little need to differentiate between URLs and URIs. However, in the non-technical literature and the World Wide Web software, the term URL is still widely used. In addition, the term "url" often appears as a synonym for URLs or URIs in non-technical literature, although it is often referred to as "http" and "https" protocols.
URI (a string that identifies an Internet resource)
