When one of your notification-enabled skills get new information, you'll get a chime and a pulsing green light on your Echo, Dot, or Show device when there's new information. This is the same way Amazon's calling service notifies you of a message. You'll just ask, "Alexa, what did I miss?" or "What are my notifications?" and Alexa will let you know what's new all at once, instead of having to query each individual skill to get new updates.
The new system will roll out for select skills and shopping updates on most Alexa-enabled devices at first, including Amazon's Echo, Echo Dot, and Echo Show. Companies in line to get the feature already include AccuWeather, The Washington Post, Just Eat and Life360. Other developers will have access to the software needed to add notifications to their own skills soon. The feature is opt-in only, which means you'll have to enable it to have it work. You can suppress notifications by putting your device into Do Not Disturb mode, too.