The Web

Taken from

The Internet Complete Reference, Second Edition, Hahn

Chapters 9 - 11: The Web


The Web is an ambitious client/server system that offers a simple, consistent inerface to the vast resources ot the Interenet.

Mailing Lists >> Usenet Newsgroups >> Gopher >> The Web

Hypertext is a technique used to link keywords in one file (such as this one) to another file (such as our homepage).

HTTP (Hypertext Transfer Protocol) is used to transfer hypertext data over the Interenet.

HTML (Hypertext Markup Language) is the programming language used to create Web pages.

URL (Uniform Resource Locator) refers to the address of hypertext.

Links: Hypertext in a Web page that, when clicked on, opens a new file.

Forms: Web page dialogue boxes that allow the user to enter text that acts as input to a CGI script.

Image Maps: A technique that allows users to link to different files by clicking on different areas of an image on a Web page.

History List: A browser feature which keeps track of the sites that you've visited and allows you to select from a list in order to return to one of those sites..

Bookmark (Favorites) List: A browser feature that allows you to save the URL's of your favorite sites so that they are more convenient to call up.

Inline Image: An image that is included as part of a Web page.

External Image: An image that can be opened in its own Window.

Regular Sounds and Video: Sound files and Video files may be downloaded and viewed by a local program.

Real-Time Sounds and Video: Use buffering techniques to play the sound or video as it is downloading.

Client-Pull: A technique used to download updated versions of a Web page at a specified time interval.

Server Push: A technique used in which the Server automatically updates the Web Page on your machine whenever necessary. Here the user must be continuously connected to the Internet.

Web Directories and Search Engines: On-line resources which allow users to search for information on the Web by using keywords. Click the Search button in your browser's toolbar for a list of the most popular search engines.

Java Applet: A program which is downloaded along with a web page and runs on the local machine.

 

Advanced Topics

URLs and Schemes: URLs have two common formats:

scheme://hostname/description

scheme://description

Common schemes include ftp, gopher, http, news, telnet.

Each Internet service has its own specific port number. Most servers use the standard port numbers although unique port numbers may be specified in the URL.

The description part of the URL specifies the pathname where the file is found.

The remainder of the information in this chapter will be discussed in tutorials as we begin to create our own Web pages.