Drupal is a very power Content Management System, otherwise known as a CMS. It handles all of your website's content and allows you to choose different ways of displaying that content to your viewers. One of the biggest advantages of using Drupal is that it is an Open Source CMS, so there are no licensing costs and the software itself is free of charge. The flexibility of the Drupal as a CMS framework is what has made it so popular with developers, while the community as a whole contributes back to Drupal's overall growth.
 
What one might know of as a Plugin in Wordpress, is actually called a Module in Drupal. Drupal modules extend Drupal's core functionality in every direction possible. Whether you are looking to build a professional business website, social networking community, an e-commerce store, a multimedia driven website, or just a personal blog, there is probably a module that does the job. The best part is, if there isn't, you can code one yourself if you know PHP, or you can find someone who does custom Drupal module development and hire them to do it for you.
 
There are also some great themes being made for Drupal these days. Originally, many of Drupal's themes were very dull and almost too mechanical for anyone to want to use their default themes, but that was mainly due to the fact that it was still a hard CMS to theme back in Drupal 5. Advancements in the core technology of Drupal have allowed for Drupal 6 to introduce a whole new set of themers and therefore themes to the Drupal community. Many of these new Drupal 6 themes are what you might see on a Wordpress website, so things are definitely coming around in the design world of Drupal as well as the development world.
 
It is quite evident that there are many reasons to why you should use Drupal, but you don't have to take my word for it, visit Drupal.org and hang out for a bit. Take a look at some of the demonstration videos and demo website available, along with checking out some of the modules and how they function through their demo sites and you make the decision for yourself. You should quickly catch on to why Drupal is definitely my CMS of choice.