Once a feature has been installed on your site, many of the components of that feature can be customized to suit your specific needs.
For example, you can add a custom field of your own to a content type that is included in the feature, or you can go in and change Views output to suit your specific needs.
When this occurs, the change is known as an override. When a feature is overridden, the word Overridden will appear next to the feature in the Feature Manager.
Feature overrides can be very tricky things as they are respective to your site only. If you click on the Recreate link, this will take you into the feature's specific control panel where a variety of customizaitons can be made or you can revert your feature back to its original state whereupon all of your customizations will be eliminated.