Explanation
When you swap deployment slots, Azure swaps the Virtual IP addresses of the source and destination slots, thereby swapping the URLs of the slots. We can easily revert the deployment by swapping back. Deployment slots are live apps with their own host names. App content and configurations elements can be swapped between two deployment slots, including the production slot. Deploying your application to a non-production slot has the following benefits: 1. You can validate app changes in a staging deployment slot before swapping it with the production slot. 2. Deploying an app to a slot first and swapping it into production makes sure that all instances of the slot are warmed up before being swapped into production. Reference:
https://docs.microsoft.com/en-us/azure/app-service/deploy-staging-slots