Drupal is basically a content management system provided by open source community for developing dynamic and theme based web application for business groups, institutions, corporate houses and many other departments or areas of work. It is used as a back end system and provides a content management framework for the developers. It is free with a number of modules already being made by developers for others to use them.
'Neerja Softwares' team witnessed a cerebral presentation last week on the Drupal topic called as “Drupal Commons”. Some of the excerpts of this presentation are shared here below. "Drupal brings people together; Commons gives them something to do". It helps us to add wikis, calendars, groups, and other social web features easily. And all that’s built on the Drupal, with all its familiar features and advantages. “Drupal Commons” is Acquia product.