Some people refer to Drupal as a so called Content Management System. But this is only partly true. Yes, Drupal provides site managers to edit and create content. But Drupal is capable of doing much more than just that.
To a developer, Drupal is a platform to build all kinds of web based applications on. These could be websites, web shops but also intranet environments, CRM applications, ERP applications and whatever it is anyone can come up with. It is extremely versatile and stands far above all other CMS-es or web development platforms available today.
Drupal powers some of the worlds biggest websites and applications. The United States government relies on Drupal for many of its critical portals and sites, such as that of the White House itself. Top institutions like Harvard and corporations like AOL trust Drupal for their critical infrastructure.
Drupal isn't just suitable for large scale projects, though. The way we see it, Drupal is just as well suited for small projects by organizations just the same. When your organization grows, your website has to grow with you. No other platform is as good and as flexible as Drupal. Making it a perfect candidate for both SME's and enterprise level organizations.