A module is code that extends Drupal's core codebase by altering existing functionality or adding new features. You can use modules contributed by others or create your own.
There are two main types of modules. Those that come shipped with Drupal Core and those that are apart of the thousands of open source modules approved by the Drupal Association and Drupal Security Team.
These are included in the default Drupal install and are located in the Extend tab under the Core directory of the Drupal install. Core modules are not to be altered in code, but settings for core modules can be configured on a site by site basis.
Full list of Core modules
Contributed modules are pieces of Drupal functionality that are created and maintained by developers in the Drupal community. The following list compiles all the contributor modules that are available to use on the Drupal 10 UCSB Web Theme.
For developers: in the event that you need a module that is not listed here, fill out the Module Request Form, as that is the only way to get a new module added to a site.
Learn more about Drupal Modules to understand the core concepts.