Upgraded URLs provide greater control and specificity over how you define the landing page and tracking parts of your final URLs.
Previously, destination URLs specified which part of your website users land on when they click your ad. They also encoded additional information for attributing performance back to the ad click. Changes to the destination URL triggered an editorial review for the ad, preventing it from running until the review was complete.
Upgraded URLs introduce shared tracking templates that separate landing page and tracking portions of the URL, allowing updates to tracking information without triggering an editorial review of the ad.