To revert all features ..
drush fra -y drush cc all
To revert a specific feature..
drush fr -y feature drush cc all
If a feature has been overridden, it can be reverted. This means that the version in the database is destroyed and the version defined in code, in your feature, is used.
If you're deploying a feature to one of you servers you would ..
git pull drush fra -y drush cc all
To update your feature ..