Google Apps is 100% web, so you and your users receive new features and updates automatically, without needing to install or update any software. However, you can still control when new features become available for users.
Scheduled Release Track
(Recommended and selected for your domain by default) Choose this track to delay releasing new features to users, giving you extra time to train your support staff and prepare users for the coming changes. Google releases features to the Scheduled Release track on Tuesdays only, at least one week after the feature was released to the Rapid Release track. Choose this track now
Rapid Release Track
Choose this track if you want users to access new features as soon as Google rolls them out to consumer users. These features have been through testing and quality assurance, but users will see them at the same time you do, before you have a chance to evaluate them for your organization. Choose this track now
Important: If you switch from the Rapid Release to Scheduled track, your users will lose access to features currently on the Rapid Release track. Make sure you first check the release calendar for current Rapid Release features.
Google releases most features to both the Rapid and Scheduled release tracks in multiple languages.