Drupal 7 Fields/CCK

Contributed modules

As we know, Drupal is an open source content management system, which is not to say that all modules written for Drupal must be free of cost. Generally speaking, Drupal modules can be categorized as follows:

• Core modules that come with Drupal core which are necessarily open source
• Custom modules that are created (tailor made) by Drupal developers for a company
• The third category, which is also the most numerous, is the contributed modules category

These are modules created by the Drupal community and usually shared under the same GNU Public License (GPL) as Drupal, which means they are free to use, even for commercial purposes.