You can think of the World Wide Web as a network of electronic files stored on computers all around the world. Hypertext links these resources together. Uniform Resource Locators or URLs are the addresses used to locate these files. The information contained in a URL gives you the ability to jump from one web page to another with just a click of your mouse. When you type a URL into your browser or click on a hypertext link, your browser is sending a request to a remote computer to download a file.
　　What does a typical URL look like? Here are some examples:
　　http://english.chinaschool.net/
　　The home page for study English.
　　ftp://rtfm.mit.edu/pub/
A directory of files at MIT available for downloading.
news:rec.gardens.roses
A newsgroup on rose gardening.
　　The first part of a URL (before the two slashes* tells you the type of resource or method of access at that address. For example:
Ø http - a hypertext document or directory
Ø gopher - a gopher document or menu
Ø ftp - a file available for downloading or a directory of such files
Ø news - a newsgroup
Ø telnet - a computer system that you can log into over the Internet
Ø WAIS - a database or document in a Wide Area Information Search database
你可以把萬維網(wǎng)想象成一個存儲在世界各地計算機上的電子文件的網(wǎng)絡(luò)。超文本把這些資源鏈接在一起。統(tǒng)一資源定位器或者稱之為URL是用來定位這些文件的地址。你只需單擊一下鼠標，URL中包含的信息就可以讓你從一個網(wǎng)頁直接跳到另一個網(wǎng)頁。當你在瀏覽器中輸入一個URL或是單擊一個超文本鏈接，你的瀏覽器就向遠程計算機發(fā)送了下載文件的請求。
一個典型的URL是什么樣的呢？以下是幾個例子。
http://english.chinaschool.net/
---一個英語學習網(wǎng)站的主頁
ftp://rtfm.mit.edu/pub/
--- 麻省理工學院一個可供下載的文件目錄
news:rec.gardens.roses
---一個有關(guān)玫瑰園藝的新聞組
一個URL的第一部分，即兩條斜線之前的部分告訴你資源類型或是那個地址的訪問方式。比如說：
Ø http - 一個超文本文檔或目錄
Ø gopher–一個鼴鼠文檔或菜單
Ø ftp – 一個可供下載的文件或這類文件的目錄
Ø news – 一個新聞組
Ø telnet – 一個可以通過因特網(wǎng)登錄的計算機系統(tǒng)
Ø WAIS – 一個廣域信息檢索數(shù)據(jù)庫中的數(shù)據(jù)庫或文檔