理解网络地址

你可以把万维网想象成一个存储在世界各地计算机上的电子文件的网络。超文本把这些资源链接在一起。统一资源定位器或者称之为URL是用来定位这些文件的地址。你只需单击一下鼠标，URL中包含的信息就可以让你从一个网页直接跳到另一个网页。当你在浏览器中输入一个URL或是单击一个超文本链接，你的浏览器就向远程计算机发送了下载文件的请求。

一个典型的URL是什么样的呢？以下是几个例子。

--- 一个英语学习网站的主页

ftp://rtfm.mit.edu/pub/

--- 麻省理工学院一个可供下载的文件目录

news:rec.gardens.roses

--- 一个有关玫瑰园艺的新闻组

一个URL的第一部分，即两条斜线之前的部分告诉你资源类型或是那个地址的访问方式。比如说：

http - 一个超文本文档或目录

gopher - 一个鼹鼠文档或菜单

ftp - 一个可供下载的文件或这类文件的目录

news - 一个新闻组

telnet - 一个可以通过因特网登录的计算机系统

WAIS - 一个广域信息检索数据库中的数据库或文档

file - 储存在本地磁盘(你的硬盘)中的文件

第二部分是典型的数据或服务所在的计算机的地址。附加的部分可能指定了文件名，连接端口，或是在数据库中检索的文本。

你可以在到网页浏览器的地址栏中(就在工具栏的下方)键入该网站的URL以进入该网站。

大多数浏览器会把你访问过的URL添加到一个专用的菜单，以便你下次再访问。这个菜单在网景导航器中被称为书签。在微软的浏览器中，它被称为收藏夹。一旦你把一个URL添加到你的清单中，当你下次再访问时，你只需点击一下列表中的名称就可以很轻松地进入该网页，而无须再键入一个完整的URL了。

你使用的大多数URL以http作为前缀，意为超文本传送协议。http使得HTML文件可以在网上传送。以下是一些关于URL的其他要点：

一个URL通常没有空格。

一个URL总使用正斜杠(//)。

如果你错误地键入了一个URL，你的浏览器将无法定位你所需要的网站或资源。如果你不想得到错误信息提示或找错地方，就请确保你输入的地址是正确的。

在那些链接上方移动你的鼠标光标，你就可以找到这个链接所指向的URL。指针将变成一只手形，这个URL也会显示在浏览器的状态栏中。状态栏通常出现在屏幕的底部。　　计算机专业英语之理解网络地址(译文)

Understanding Web Addresses

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:

The home page for study English.

ftp://rtfm.mit.edu/pub/

A directory of files at MIT available for downloading.

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:

http - a hypertext document or directory

gopher - a gopher document or menu

ftp - a file available for downloading or a directory of such files

news - a newsgroup

telnet - a computer system that you can log into over the Internet

WAIS - a database or document in a Wide Area Information Search database

file - a file located on a local drive (your hard drive)

The second part is typically the address of the computer where the data or service is located. Additional parts may specify the names of files, the port to connect to, or the text to search for in a database.

You can enter the URL of a site by typing it into the Location bar of your web browser, just under the toolbar.

Most browsers record URLs that you want to use again, by adding them to a special menu. In Netscape Navigator, it’s called Bookmarks. In Microsoft Explorer, it’s called Favorites. Once you add a URL to your list, you can return to that web page simply by clicking on the name in your list, instead of retyping the entire URL.

Most of the URLs you will be using start with http which stands for Hypertext Transfer Protocol*. http is the method by which HTML files are transferred over the Web. Here are some other important things to know about URLs:

A URL usually has no spaces.

A URL always uses forward slashes (//).

If you enter a URL incorrectly, your browser will not be able to locate the site or resource you want. Should you get an error message or the wrong site, make sure you typed the address correctly.

You can find the URL behind any link by passing your mouse cursor over the link. The pointer will turn into a hand and the URL will appear in the browser’s status bar, usually located at the bottom of your screen.