http://www.pierobon.org/iis/url.htmIt is a good question, I've ever wanted to ask someone but I didn't do it. Thanks! Just google it! URL vs URI
Uniform Resource Locator--------------------------------------------------------------------------------What is an URL An Uniform Resource Locator (URL) is the term used to identify an Internet resource, and can be specified in a single line of text.What is an URN An Uniform Resource Name (URN) is the term used to identify an Internet resource, without the use of a scheme, and can be specified in a single line of text.What is an URI An Uniform Resource Identifier (URI) is used by a browser to identify a single document, and it too can be specified in a single line of text.URL vs. URN vs. URI The difference between the three is subtle. An URL refers to a Web page, including the scheme, but without a name location. An URN may also include the location of a code fragment. An URI refers to a Web page including the location of the code fragment, if one exists, and the scheme. URL http://www.gleaners.org/faq.html URN www.gleaners.org/faq.html#Q04 URI http://www.gleaners.org/faq.html#Q04 Because Web servers allow for default documents and do not require a scheme to retrieve a document, the subtle difference between an URL and an URN and an URI is hard to tell. URL is now used as the generic term.Additional information on URL specification may be found here.I understand the difference between an URL and an URI. What are the different parts of an URL?
What is an URL An Uniform Resource Locator (URL) is the term used to identify an Internet resource, and can be specified in a single line of text. What is an URN An Uniform Resource Name (URN) is the term used to identify an Internet resource, without the use of a scheme, and can be specified in a single line of text. What is an URI An Uniform Resource Identifier (URI) is used by a browser to identify a single document, and it too can be specified in a single line of text. URL vs. URN vs. URI The difference between the three is subtle. An URL refers to a Web page, including the scheme, but without a name location. An URN may also include the location of a code fragment. An URI refers to a Web page including the location of the code fragment, if one exists, and the scheme. URL http://www.gleaners.org/faq.html URN www.gleaners.org/faq.html#Q04 URI http://www.gleaners.org/faq.html#Q04 Because Web servers allow for default documents and do not require a scheme to retrieve a document, the subtle difference between an URL and an URN and an URI is hard to tell. URL is now used as the generic term. Additional information on URL specification may be found here.
What is an URL An Uniform Resource Locator (URL) is the term used to identify an Internet resource, and can be specified in a single line of text. What is an URN An Uniform Resource Name (URN) is the term used to identify an Internet resource, without the use of a scheme, and can be specified in a single line of text. What is an URI An Uniform Resource Identifier (URI) is used by a browser to identify a single document, and it too can be specified in a single line of text. URL vs. URN vs. URI The difference between the three is subtle. An URL refers to a Web page, including the scheme, but without a name location. An URN may also include the location of a code fragment. An URI refers to a Web page including the location of the code fragment, if one exists, and the scheme. URL http://www.gleaners.org/faq.html URN www.gleaners.org/faq.html#Q04 URI http://www.gleaners.org/faq.html#Q04 Because Web servers allow for default documents and do not require a scheme to retrieve a document, the subtle difference between an URL and an URN and an URI is hard to tell. URL is now used as the generic term. Additional information on URL specification may be found here.
Just google it! URL vs URI
An Uniform Resource Locator (URL) is the term used to identify an Internet resource, and can be specified in a single line of text.What is an URN
An Uniform Resource Name (URN) is the term used to identify an Internet resource, without the use of a scheme, and can be specified in a single line of text.What is an URI
An Uniform Resource Identifier (URI) is used by a browser to identify a single document, and it too can be specified in a single line of text.URL vs. URN vs. URI
The difference between the three is subtle. An URL refers to a Web page, including the scheme, but without a name location. An URN may also include the location of a code fragment. An URI refers to a Web page including the location of the code fragment, if one exists, and the scheme. URL http://www.gleaners.org/faq.html
URN www.gleaners.org/faq.html#Q04
URI http://www.gleaners.org/faq.html#Q04 Because Web servers allow for default documents and do not require a scheme to retrieve a document, the subtle difference between an URL and an URN and an URI is hard to tell. URL is now used as the generic term.Additional information on URL specification may be found here.I understand the difference between an URL and an URI. What are the different parts of an URL?
Web上可用的每种资源 - HTML文档、图像、视频片段、程序等 - 由一个通过通
用资源标志符（Universal Resource Identifier, 简称"URI"）进行定位。 URI一般由三部分组成：访问资源的命名机制。
存放资源的主机名。
资源自身的名称，由路径表示。
考虑下面的URI，它表示了当前的HTML 4.0规范： http://www.webmonkey.com.cn/html/html40/ 这个URI是这样的：这是一个可通过HTTP协议访问的资源，位于主
机www.webmonkey.com.cn上，通过路径“/html/html40”访问。在HTML文档中
其它资源包括"mailto"（收发email）和"ftp"（FTP访问）。 这是URI的另一个例子，指向一个用户的邮箱：Joe Cool注：大多数读者可能熟悉"URL"，而不是URI。URL是RUI命名机制的一个子集。2.1.2 片段标志符
有的URI指向一个资源的内部。 这种URI以"#"结束，并跟着一个anchor标志
符（称为片段标志符）。例如，下面是一个指向section_2的URI：http://somesite.com/html/top.htm#section_2 2.1.3 相对URI
相对URI 不包含任何命名规范信息。它的路径通常指同一台机器上的资源。相
对URI可能含有相对路径（如，“..”表示上一层路径），还可能包含片段标
志符。为了说明相对URI，假设我们有一个基本的URI
"http://www.acme.com/support/intro.htm"。下面的链接中使用了相对URI： Suppliers它扩展成完全的URI就是 "http://www.acme.com/support/suppliers.htm"，
下面是一个图像的相对URI：它扩展成完全的URI就是 "http://www.acme.com/icons/logo.gif"。 在HTML中，URI被用来：链接到另一个文档或资源(参看A和LINK元素)。
链接到一个外部样式表或脚本(参看LINK和SCRIPT元素)。
在页内包含图像、对象或applet(参看IMAG、OBJECT、APPLET和INPUT
元素)。
建立图像映射(参看MAP和AREA元素)。
提交一个表单(参看FORM)。
建立一个框架文档(参看FRAME和IFRAME元素)。
引用一个外部参考(参看Q、BLOCKQUOTE, INS和DEL元素)。
指向一个描述文档的metadata(参看HEAD元素)。URL：
URL是Uniform Resource Location的缩写，译为“统一资源定位符”。通俗地说，URL是Internet上用来描述信息资源的字符串，主要用在各种WWW客户程序和服务器程序上，特别是著名的Mosaic。采用URL可以用一种统一的格式来描述各种信息资源，包括文件、服务器的地址和目录等。 ◇ URL的格式URL的格式由下列三部分组成： 第一部分是协议（或称为服务方式）；
第二部分是存有该资源的主机IP地址（有时也包括端口号）；
第三部分是主机资源的具体地址。，如目录和文件名等。
第一部分和第二部分之间用“：//”符号隔开，第二部分和第三部分用“/”符号隔开。第一部分和第二部分是不可缺少的，第三部分有时可以省略。◇ URL示例 文件的URL：
用URL表示文件时，服务器方式用file表示，后面要有主机IP地址、文件的存取路径（即目录）和文件名等信息。有时可以省略目录和文件名，但“/”符号不能省略。
例一：file://ftp.yoyodyne.com/pub/files/foobar.txt
代表存放主机ftp.yoyodyne.com上的pub/files/目录下的一个文件，文件名是foobar.txt。
例二：file://ftp.yoyodyne.com/pub
代表主机ftp.yoyodyne.com上的目录/pub。
例三：file://ftp.yoyodyne.com/
代表主机ftp.yoyodyne.com上的根目录。Gopher的URL：
Gopher服务器有可能使用特殊的端口，在这种情况下，主机IP地址与端口之间要用“：隔开。
例一：gopher://gopher.yoyodyne.com/
表示主机gopher.yoyodyne.com上的gopher服务器。
例二：gopher://gopher.banzai.edu:1234
表示主机gopher.banzai.edu上的gopher服务器，在端口1234上。网络新闻的URL：
利用URL表示网络新闻组时，如果是usenet的话只要指定出新闻组的名字即可。
例如：news:rec.gardening
表示usenet上的rec.gardening新闻组（园艺）。HTTP的 URL：
使用超级文本传输协议HTTP，提供超级文本信息服务的资源。
例一：http://www.peopledaily.com.cn/channel/welcome.htm
其计算机域名为www.peopledaily.com.cn。超级文本文件（文件类型为.html）是在目录/channel下的welcome.htm。这是中国人民日报的一台计算机。
例二：http://www.rol.cn.net/talk/talk1.htm
其其计算机域名为www.rol.cn.net。超级文本文件（文件类型为.html）是在目录/talk下的talk1.htm。这是瑞得聊天室的地址，可由此进入瑞得聊天室的第1室。◇ URL的缺点最大的缺点：当信息资源的存放地点发生变化时，必须对URL作相应的改变。因此人们正在研究新的信息资源表示方法，例如：URI(Universal Resource Identifier)即“通用资源标识”（参见RFC 1630）、URN（Uniform Resource Name）即“统一资源名”和URC（Uniform Resource Citation）即“统一资源引用符”等。
An Uniform Resource Locator (URL) is the term used to identify an Internet resource, and can be specified in a single line of text. What is an URN
An Uniform Resource Name (URN) is the term used to identify an Internet resource, without the use of a scheme, and can be specified in a single line of text. What is an URI
An Uniform Resource Identifier (URI) is used by a browser to identify a single document, and it too can be specified in a single line of text. URL vs. URN vs. URI
The difference between the three is subtle. An URL refers to a Web page, including the scheme, but without a name location. An URN may also include the location of a code fragment. An URI refers to a Web page including the location of the code fragment, if one exists, and the scheme. URL http://www.gleaners.org/faq.html
URN www.gleaners.org/faq.html#Q04
URI http://www.gleaners.org/faq.html#Q04 Because Web servers allow for default documents and do not require a scheme to retrieve a document, the subtle difference between an URL and an URN and an URI is hard to tell. URL is now used as the generic term. Additional information on URL specification may be found here.
An Uniform Resource Locator (URL) is the term used to identify an Internet resource, and can be specified in a single line of text. What is an URN
An Uniform Resource Name (URN) is the term used to identify an Internet resource, without the use of a scheme, and can be specified in a single line of text. What is an URI
An Uniform Resource Identifier (URI) is used by a browser to identify a single document, and it too can be specified in a single line of text. URL vs. URN vs. URI
The difference between the three is subtle. An URL refers to a Web page, including the scheme, but without a name location. An URN may also include the location of a code fragment. An URI refers to a Web page including the location of the code fragment, if one exists, and the scheme. URL http://www.gleaners.org/faq.html
URN www.gleaners.org/faq.html#Q04
URI http://www.gleaners.org/faq.html#Q04 Because Web servers allow for default documents and do not require a scheme to retrieve a document, the subtle difference between an URL and an URN and an URI is hard to tell. URL is now used as the generic term. Additional information on URL specification may be found here.