Contributed or contrib modules are Drupal plugins that help build, extend or enhance core functionality. Some of the most popular Drupal modules are:

• Panels: It helps you to define the complete lay out of the site by just dragging and dropping.
• Content Construction Kit (CCK): It allows you to define data fields, and lets you add media files and defines how they will be displayed.
• Token: This is an API used by other modules where terms like [user] can be used in the txt and can be replaced with the proper value.
• Views: It lets you display and define any form of content in any format.
• Pathauto: It lets you set up patterns for SEO purposes, like URLs.