Submitted by mig5 on November 6, 2009 - 11:58
Features are a method of exporting the mechanics or functionality of your site into 'meta-modules' that can be installed and enabled on any site, immediately providing that functionality to the different site.
Whereas CCK and Views add functionality to a site, Features can (for example) export node types, the CCK fields, various Views and other settings and allow you to turn on that functionality as a 'feature' on another site.
Essentially it is a way of leveraging functionality traditionally stored in the database, and exporting it into code, which can then be kept under version control etc.
Read more about Features:
http://drupal.org/node/580026
https://community.openatrium.com/documentation-en/node/449