With their announcement today of iOS 9, Apple unveiled a new and improved Siri, as well as a new context-sensitive feature called Proactive.
During their reveal of iOS 9, Apple showed off the new enhancements coming to Siri, as well as a new feature designed to enhance how your devices work for you. Siri is getting a new interface that makes it easier to use, and is becoming more intelligent.
For instance, when you ask for photos from a particular place and time, Siri will open those photos in the Photos app. Reminders are more contextual, understanding what you're doing and the apps you're using. Developers will also get access to an API in order to integrate search into their apps, with deep links directly to their applications and back links to search results.
Proactive is an extension of this new contextual awareness. It uses context-sensitive data about your location, connections, and the time. It can do things like show you what's playing in Music when you plug in your headphones, and automatically adds invites to your calendar. Proactive can also search your email for phone numbers of non-contacts. Swiping left of your Home screen, Proactive will show you people you might want to contact, as well as apps you may want to launch based on what you're doing and the time of day.
It can also do things like look at traffic on an upcoming route before you leave, and tell you to leave earlier. All of this data is not associated with your Apple ID, not shared with Apple or third-party services, and is anonymized with a random identifier.