Enable deployment slots for zero downtime deployment

The App Settings and Connection Strings that are marked as “Slot” are read from the Production slot and applied to the site in the Staging slot

Both slots have their own Application Settings, but the default behavior is for the Application Settings to follow the deployment when you swap

azure deployment slot According to Microsoft, deployment slots could be used to achieve zero-downtime deployments, prewarming, and easy fallbacks

azure deployment slot setting When you deploy your website to Azure App Services, you can benefit from the out of the box support for deployment slots