Fantastico; an easy way to install WordPress, or a fantastic(o) way to invite hackers into your site?
The answer is: Both.
Fantastico is a front end script visually similar to most modern operating systems. Point and click on the appropriate icon, and you have a quick and easy WordPress installation.
Most web hosts offer this to make installation of WordPress (and other programs) easy.
Unfortunately for you (but not so for hackers wanting access), the easy to use Fantastico is incredibly unsecure.