As briefly mentioned before, deployment slots are an Azure PaaS feature which allows for a zero-downtime swap between your application environments. A deployment slot is, essentially, a replica of your production environment, which can be swapped with production by a DNS change handled by the Azure platform.
This feature is commonly used by developers to deploy production-ready code to a staging slot for final testing. If the staging deployment passes the tests, it can be promoted to production. Furthermore, if any issues are reported after deployment to production, the slots can be swapped back (since your former production environment is still available in the staging slot) with no downtime. This allows you to revert back ...
