So what does this new feature do ? It allows web applications to send alerts which go straight to the Notification Center, even when Safari isn’t running.
Only a handful of websites have activated the feature, though others are expected to follow suit as soon as Mavericks goes public, which some watchers think might happen during today’s event…
This feature was first spotted by MacRumors, Safari push notifications have gone live on the NBA.com ,Pinterest.com and the New York Times website. Push notifications is just one in a series of enhancements and under-the-hood improvements to Safari in Mavericks.
These web-based alerts let you subscribe to a website to get notified about, for example, updates to developing stories, after new content has been published and so forth.
Again, web applications and websites that have registered for the Safari push notifications are able to push these alerts to the Notification Center on their Macs even when Safari is not running, allowing for a better user experience.