What Is Drupal?
Drupal is used to build web sites. It's a highly modular, open source web content management framework with an emphasis on collaboration. It is extensible, standards-compliant, and strives for clean code and a small footprint. Drupal ships with basic core functionality, and additional functionality is gained by the installation of modules. Drupal is designed to be customized, but customization is done by overriding the core or by adding modules, not by modifying the code in the core. It also successfully separates content management from content presentation.
Drupal can be used to build an Internet portal; a personal, departmental, or corporate web site; an e-commerce site; a resource directory; an online newspaper; an image gallery; and an intranet, to mention only a few. It can even be used to teach a distance-learning course. A dedicated security team strives to keep Drupal secure by responding to threats and issuing security updates. And a thriving online community of users, site administrators, designers, and web developers work hard to continually improve the software.