What is URI?
A URI, short for Uniform Resource Identifier, is a short string identifying a resource on a network (such as a Web resource) physical or abstract syntax which meets a standard of Web development for the World Wide Web (see RFC 3986). The standard was previously known under the term IDUs.
The IETF was first defined in RFC 2396 based on proposals by Tim Berners-Lee (RFC 1630). Updated by RFC 2732 and revised several times under the title rfc2396bis, RFC 3986 defines the URI in January 2005.
The acronym URI is typically used to designate such a string. For example urn: ietf: rfc: 2396 is a URI identifying the RFC 2396.
URIs are the core technology of the World Wide Web for all Web hyperlinks are expressed as URIs.
URI – Principle
A URI must identify a resource permanently, even if the resource is moved or deleted.
URI – Applications
So far the only URI URLs are finding a practical application. [Ref. needed] However, one can see the barcode as a metaphor for URI in the physical world: a bar code does not locate a product, but identifies it (although it identifies all copies of a product not each individual copy, which is the work of the serial number, which is not systematic but restricted to expensive products).
Relationship with URLs and URNs
A URI can be of type “locator” or “name” or both.
A Uniform Resource Locator (URL) is a URI that, besides the fact that it identifies a resource on a network, provides the means to act on a resource or to obtain a representation of the resource by describing its access mode Primary or “location” network. For example, the URL http://www.wikipedia.org/ is a URI that identifies a resource (Wikipedia homepage) and involves a representation of that resource (an HTML page encoded characters) can be obtained via HTTP from a network host named www.wikipedia.org.
A Uniform Resource Name (URN) is a URI that identifies a resource by name in a namespace. A URN can be used to talk about a resource without prejudice to its location or how to reference it. For example, the URN urn: isbn :0-395-36341-1 is a URI that is an issue of the International Standard Book Number (ISBN), can refer to a book, but does not suggest where or how to get an actual copy.
The current view of the working group that oversees URIs is that the terms URL and URN are context-dependent aspects of URI and that it rarely needs to distinguish between the two . In technical publications, especially the standards erected by the IETF and W3C, the term URL has not been recognized for a long time because it was rarely necessary to distinguish between URLs and URIs. However, in non-technical software and the World Wide Web, the term URL is still omnipresent. Moreover, the word address, which has no formal definition, is often used in non-technical publications as synonymous with URL or URI, although generally it refers to the protocols’ http ‘and’ https ‘.
URL – Uniform Resource Locator
What Is URL?
The acronym URL (the Uniform Resource Locator), which replaces the term informally address, means a string of characters used to direct the resources of the World Wide Web: HTML document, image, sound, Usenet, mailbox, etc.. URLs are a subset of uniform resource identifiers (URI), the only URI have found practical application [ref. necessary]. The format (syntax) of a URL is described in RFC 3986.
Since the URLs have been designed for the web and they are used to identify pages and websites, they are also called web addresses. The article on the web addresses on the identity of websites and the technical, economic and legal related, and different translations in French acronym URL.
This article describes the URLs as a standard technique: all the forms they may take, especially for pointing out the Web resources, as well as key technical purposes.
The URLs have been invented in order to indicate with a notation (hence the adjective “uniform”) to web browsers how to access all Internet resources.
Each link of the web is built with the URL of the resource pointed, inserted with a certain syntax in a source document (or a program or a user interface) that contains it to indicate the location of another resource (a document ) or fragment resource (an anchor target in that other document). When an active link, the browser may submit its URL in the status bar (see below for the “address bar”).
A hyperlink can also be constructed externally to the document itself, in a database referencing all pairs (URL source, URL target) between an area activated a source document and an anchor target in a document (which may be the same as the source document containing the activated area).
The link can also be constructed in reverse, by inserting the target document in the URL of the source area.
Each browser has an “address bar” displaying the URL of the resource accessed. It is also possible to enter a URL into the address bar to access a resource that we know the URL.
If the media allows it, you can also find the URL to a link by moving the mouse over the image or the appropriate text. The URL can then be presented in a tray or an information bubble.
Web browsers keep a history of visited URL. This allows them to recognize and present distinctively hyperlinks to resources already consulted.
Just a web browser to keep the URL of a resource to provide a list of favorites (or bookmarks). When as a resource exists, browsers also retain, which displays the title of a page rather than the URL.
A URL is a string combining the information necessary to tell software how to access an Internet resource. This information may include the communication protocol, a user name, password, IP address or domain name, port number TCP / IP, a path, a query.
The information needed will vary depending on the resource and context of use of the URL. In addition a fragment identifier may be added at the end of a URL to identify an item within the resource. Although the fragment identifier does not formally part of the URL, it is also described in this section and technical standards.
An absolute URL is used to specify how to access a resource independently of any context where it can be specified or transmitted. It begins with an indication of a representation scheme (specific communication protocol used to access this resource), followed by all the parameters for locating the network service hosting the resource, and allows to specify this service on behalf of a resource to treat, transmit data processing, routing and retrieval of data, then specify how much of that may result will be used.
The protocols using a hierarchical path allow the use of relative URLs. A relative URL does not contain any protocol or domain name. These are deducted from the URL of the resource containing the relative URL.
Relative URLs are frequently used for hyperlinks within the same website. If the document contains the URL relative URL http://fr.wikipedia.org/wiki/Web Navigator, this corresponds to http://fr.wikipedia.org/wiki/Navigateur. Relative URLs are directly inspired by the syntax of UNIX file systems. The use of relative URLs allows you to copy an entire web site on another Web server without having to change the URL.
*. / Is the current folder;
* .. / Is the parent folder;
* / Matches the root folder.
Study: From Wikipedia, the free encyclopedia. The text is available under the Creative Commons.
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