Explanation

App1: Canary deployment
With canary deployment, you deploy a new application code in a small part of the production infrastructure.
Once the application is signed off for release, only a few users are routed to it. This minimizes any impact.
With no errors reported, the new version can gradually roll out to the rest of the infrastructure.
App2: Rolling deployment:
In a rolling deployment, an application's new version gradually replaces the old one. The actual deployment happens over a period of time. During that time, new and old versions will coexist without affecting functionality or user experience. This process makes it easier to roll back any new component incompatible with the old components.