What is a resource available on UriWeb-HTML document, images, video clips, programs, etc. - by a Universal Resource Identifier, a referred to as "URI"). URI is generally consisting of three parts: access to the naming mechanism. Store the host name of the resource. The name of the resource itself is represented by the path. Consider the following URI, it expressed the current HTML 4.0 specification: http://www.webmonkey.com.cn/html/html40/ This URI is this: This is a resource accessible through the HTTP protocol, located in the host WWW .Webmonkey.com.cn, via path "/ html / html40" access. Other resources in the HTML document include "Mailto" and "FTP". This is another example of the URI, pointing to a user's mailbox: Joe Cool Note: Most readers may be familiar with "URL" instead of URI. The URL is a subset of the RUI naming mechanism. 2.1.2 The clip flag The URI of the icon points to the inside of a resource. This URI ends with "#" and follows an Anchor flag (called a clip flag). For example, the following is a URI: http://somesite.com/html/top.htm#section_22.1.3 relative URI does not contain any naming specification information relative to the URI relative URI. Its path usually refers to resources on the same machine. The relative URI may contain a relative path (eg, "," indicating the last layer path), and may also contain the clip flag. To illustrate the relative URI, suppose we have a basic URI "http://www.acme.com/support/intro.htm". The following link uses the relative URI: Suppliers It expands to complete URI is "http://www.acme.com/support/suppliers.htm", below It is an image of the relative URI: 
It extends complete URI is "http://www.acme.com/icons/logo.gif ". In HTML, the URI is used: link to another document or resource (see A and LINK elements). Link to an external style sheet or script (see LINK and Script Elements). Contains images, objects, or applets in the page (see IMAG, Object, Applet, and INPUT). Establish an image mapping (see MAP and Area elements). Submit a form (see FORM). Create a framework document (see Frame and IFrame Elements). Reference an external reference (see Q, Blockquote, INS and DEL elements). Point to a metadata describing the document (see HEAD Element).
URL: URL is an abbreviation for UNIFORM Resource Location, translated as "Unified Resource Locator". In practice, the URL is a string used to describe information resources on the Internet, mainly in a variety of WWW clients and server programs, especially famous MOSAICs. URLs can be used to describe a variety of information resources, including files, servers, and directory, etc. ◇ URL format URL format consists of the following three parts: The first part is an agreement (or a service method); the second part is the host IP address of the resource (sometimes the port number); the third part is the host Resource specific address. Such as catalogs and file names, etc. The first part and the second portion are separated from the ": //" symbol, the second portion and the third portion are separated by "/" symbol. The first part and the second part are indispensable, and the third part can sometimes be omitted. ◇ URL of the URL sample file: When using the URL represents the file, the server mode is represented by file, and there is information such as the host IP address, file access path (ie, directory) and file name. Sometimes you can omit the directory and file name, but "/" symbols cannot be omitted. Example 1: file: //ftp.yoyodyne.com/pub/files/foobar.txt represents a file in the Pub / Files / Directory on the host ftp.yoyodyne.com, the file name is foobar.txt. Example 2: file: //ftp.yoyodyne.com/pub represents directory / PUB on the host ftp.yoyodyne.com. Example 3: file: //ftp.yoyodyne.com/ represents the root directory on FTP.YOYODYNE.COM. Gopher's URL: Gopher server is likely to use special ports, in which case the host IP address and port are used ": separated. Example 1: gopher: //gopher.yoyodyne.com/ Indicates the host Gopher. Gopher server on yoyodyne.com. Example 2: Gopher: //gopher.banzai.edu: 1234 Represents the Gopher server on Gopher.banzai.edu on the host, on port 1234. Network News URL: Using URL Represents Network News Group If you are using, if you want to specify the name of the newsgroup. For example: news: rec.gardening indicates the Rec.Gardening newsgroup (garden) .http URL: Urdree Transfer Protocol HTTP: Super Text The resources of information services. Example 1: http://www.peopledaily.com.cn/channel/welcome.htm Its computer domain name is www.people.com.cn. Super text file (file type is .html) is in the directory / CHANNEL under Welcome.htm. This is a computer in the People's Daily. Example 2: http://www.rol.cn.net/talk/talk1.htm Its computer domain name www.rol.cn.net The super text file (file type is .html) is Talk1.htm under the directory / Talk. This is the address of the Ryz chat room, which can be entered the first room of the Rye chat room. ◇ URL's shortcomings the biggest shortcomings : When the location of the information resource changes, the URL must be changed accordingly.
