Drupal is just one of the Addoncgi cgi scripts that I don't understand. What is it for? Can anyone explain what it is supposed to be used for?

Drupal is a CMS, like PHP-Nuke and so on, if you want to make a portal you could use it.

btw, you shouldn't use the addon script things, you should use fantastico instead. The addon scripts had some bugs in them.

It's a fairly popular CMS system. There's a demo of it here (along with some reviews). When you don't know what something is, it's best to google for the source site for more information. In this case, it's http://www.drupal.org/ .

What is Drupal? I know it is a content management system or whatever.
Why should we use Drupal?
How is Drupal useful?
Is it better than writing our own PHP/XHTML/CSS?

Should I use Drupal if I want to take over the Internet?

http://en.wikipedia.org/wiki/Drupal

That should give you the answer.

Content Management Systems(CMSes) relieve you of needing to write your own code, so updating a page, removing an announcement, and adding a link or download.

Of course you could write your own CMS that tailors to your needs. That's what I did for OS Advocacy III.

Unless you're using Coranto, Content Management Systems show you are a lazy admin who doesn't want to put an actual unless you try to make a unique template, and that means much harder work than a Coranto based page using Nvu or Dreamweaver to create a page