Introduction to Web Browsing

Using a web browser to view the Internet

Our primary tool for viewing the content on the Internet will be the web browser. This web browser is an application (or computer program) which will allow us to view various types of files.

This class will involve learning how to read, use and navigate the Internet with a web browser. The web browsers we will use are called Mozilla Firefox and Microsoft Internet Explorer. Many of the concepts and skills from Introduction to the Internet will be applicable to other web browsers like Netscape Communicator and the America Online environment.

Master of your domain!

URL, http://, domain name, dot com, web address, .edu, .net . . ."ARGH"!

A URL is an acronym standing for Universal Resource Locator. The URL is the web address which locates a specific file (or resource) on the Internet. The URL for this page can be seen in the location bar toward the top of the browser. It should say something like:

http://www.bu.edu/cpr/classes/internet/browser.html

Web address, domain, location, http://-thing are all words to say the same general thing: the URL for a page.

Dissecting a URL

You can dissect a URL to find out more about the location. We will dissect the Center for Psychiatric Rehabilitation's home page URL as an example:

http://www.bu.edu/cpr/index.html

http://
This stands for HyperText Transfer Protocol. This just says that we can transfer (over the Internet) hypertext files onto our computers. We will go into more detail about Hypertext files later. (This is usually no longer needed in most browsers.)

www.bu.edu/

This is the Boston University domain name. Domain names often represent the main website that a sub-website may be located on. The Center is part of Boston University, so it is one of the many sub-websites located within the Boston University domain. In this situation, www stands for World Wide Web, bu stands for Boston University; and edu shows that it's an educational institution. The segments of the domain name are separated by periods (often we no longer need to type in the www now).

cpr/

Our page is located in the cpr directory on the Boston University server. This is similar to being located in a cpr folder on you computer.index.html; this is the actual file name and extension of the Center's home page. The home page is an HTML file: HyperText Markup Language. Its name is index.

In conclusion, we know that the Center's homepage is a hypertext document, located on the world wide web on the Boston University website in the cpr directory and is named index.html.

The URL of a specific web page will allow us to access that web page on the world wide web from any computer with Internet access. By typing in the URL for the Introduction to Web Browsing lesson, we can view the lesson on the computer.

Practice:

1. Go to your desktop and double click on the Internet Explorer icon (there is a picture of it at the beginning of the lesson).

2. Click File from the main menu with your mouse pointer. Select Open.

3. Type the following URL into the text box on the popup window: http://www.bu.edu/cpr/classes/internet/browser.html

4. Click the Open button. You can also type the URL directly into the Location window

This will bring you to the the web page of this handout.
(This practice exercise is performed slightly different in Mozilla).

File Types: html, gif, jpg, txt . . .

Web browsers view files published to the Internet. Common file types include: text, images, and hypertext. You can click on the hyperlinks below for a comparison of the different file types:

Although they are very different, all of the above examples have the same file name: sample. The file extensions let us know what type of files they are. The "txt" after the first example let us know that it is a text file. The "html" after the last example let us know that it is a hypertext file. We typically say the full file name (ex: index.html) when referring to individual files so we don't get confused. Here are some common file extensions we may interact with, and what type of file they are representing. This is not expected to be memorized, but just used as a reference:

File Not Found?

The URL is a highly descriptive and precise location of a single file on the vast Internet. Similar to a conventional mailing address, if we leave a segment of a URL out or if we type in an incorrect URL, we will not be able to find the file. If a page similar to the one on the left appears when you try to type in a URL from scratch, here's what you should do:

1. Double check the URL from the source (magazine article, handwritten note, email from a friend).

2. Double check your accuracy in retyping the full URL in the Open File popup window.

3. Make sure that there are no extra spaces, that the URL is case sensitive (capitals and lowercase letters count).

4. Make sure that you use a colon ":" (not a semicolon ";") after the http, and that you use periods (not commas) to separate domain names and file names.

There could be a million reasons why URL's are no longer functioning. The best thing to do is to re-find the information, or to locate the information from a different source. We will discuss how to web-search in future lectures.

Proceed to the next lesson: Hypertext and Hyperlinks . . .

Site and course content by Kevin Berner, edited by Lori Wallace and Donna Wilbur