With traditional notifications you could be alerted when a message came in, an invitation was sent your way, news was shared with you, etc. but you couldn't do anything about it, not without leaving your current activity to switch apps, take action, and then find your way back. With interactive notifications in iOS 8, however, you can reply to a message right from the banner, accept an invitation right from the lock screen, or like a piece of news directly from Notification Center. Whether you're editing a business document or playing a game, interruption is minimized and app switching is potentially eliminated altogether. So, how does it work?