The Digital Research Initiative

The Digital Research Initiative
The University of North Carolina at Chapel Hill

Click on the above graphic to see an excellent example of the Australian National University Library's "Publishing on the World Wide Web" site at http://info.anu.edu.au/courses/html/demo/ The graphic has been reproduced from Australian National University Library's web-site athttp://info.anu.edu.au/courses/html/demo/demo17.html only for academic discussion, evaluation, research and complies with the copyright law of the United States as defined and stipulated under Title 17 U. S. Code.

Uniform Resource Locator (URL)

A URL is the "address" of a document, image, sound, video clip or other resource on the World Wide Web.

This is a complete URL:

http://www.unc.edu/~daikat/URLparts.html

These are its parts:

Protocol: http
Host name: www.unc.edu
Directory path: ~daikat
File name: URLparts.html

Notice that the file name in this URL has some upper case letters. On the Web, upper and lower case letters in a file name are often treated as different characters, so "urlparts.html" might not work.

URL Scheme: [protocol][host][file]

[protocol]
[host]

[file]
You can end a URL with the name of the Web server, a subdirectory on that computer, or a specific file. File names on the Web genererally end with ".html" or ".htm" or ".txt"
If you do not specify a file name, your Web browser will look for a file named "index.html" in that directory. If it does not find one, it may give you a list of files in the directory.
Netscape can also open a file on your own desktop computer. In this case it is not using http:, and the "Location" field looks like this:

URL Examples

http://www.unc.edu/~daikat/URLparts.html
ftp://ftp.ncsa.uiuc.edu/

In addition to HTTP, many Web sites also use other Internet protocols like MAILTO: and FTP. FTP stands for File Transfer Protocol, and is used to copy a file from one computer to another even if the receiving computer cannot display that file on its screen. FTP can move binary files -- sound clips, executable programs and graphics -- as well as text.
mailto: daikat@email.unc.edu

With Netscape and other Web browsers it is easy to send mail, but harder to check your incoming mail.

HTML Documents & HTTP Servers

Hypertext Markup Language (HTML)

Markup language used by the WWW browser programs for formatting documents on the display, including images, movies, audio, and text.
Also displays links to additional documents on the WWW (or locally).

Hypertext Transfer Protocol (http)

The "http" at the beginning of a URL is a protocol that lets your browser transfer files from remote servers to graphically display web content through your browser on your monitor. The protocol makes the connection to the server, provides the information, then breaks the connection.
"Browsing" a document for many minutes does not mean you are literally connected to the server for those minutes. The page has been loaded onto the browsing (client) computer, and is "cached" there until you reload the page or go to another page on the Web.

File Transfer Protocol (FTP)

FTP client software allows you to transfer files between your hard drive and a remote server. For instance, you could put your personal home page up on the Web by transferring files from your hard drive to a Web server, or you can download programs from your favorite shareware site -- fast. The Fetch program on Macs and the WS_FTP program on PCs are examples of FTP programs.

Forms Processing and the Common Gateway Interface

HTML has markup tags to display fill-out forms with information that is returned to the http server.
The http server in turn has programs that process the information. Such programs, sometimes called Common Gateway Interface (CGI) scripts, can copy information from the forms into a file or database, return requested information from a file or a database, or perform other operations. Also known as cgi binaries, cgi bins, cgi scripts, or cgi's, these programs (usually) reside in a different directory than the HTML pages of a Web site. When a client makes a request for a file residing in the "cgi bininaries" directory, instead of returning the contents of the requested file, the server instead executes (runs) that script or program and returns to the client the output of the program (for instance, the results of your filling out a form or your taking an online quiz). These results are typically displayed in HTML.

This site made by

This site was created especially for students of the UNC School of Journalism's
JOMC 050 Class, and anyone else who may be interested.
For more information, please contactdaikat@email.unc.edu
Last Updated: Thu, 10 Dec 1998 22:05:01 GMT