What are Push Notifications in Windows Phone 7?

"To better understand PN, we need to remember that the end user experience is the first and foremost characteristic of Windows Phone (WP) design. A positive end-user experience is the number one WP design goal. This tenet has major implications for how WP works, not just in terms of its new UI and the interaction model it drives, but also with the application platform (the API for developers). Push notification is one obvious mechanism to ensure a coherent and deterministic end user behavior that allows you to communicate with the end user even when your phone application is not running on the phone."

If you're wondering how exactly Push Notifications (PN) work in Windows Phone 7 compared to previous versions of the OS, this blog post should be enlightening. And in the end you'll be clear on the difference between a Tile Notification and a Toast Notification!