Service Fabric uses two XML files - the Application Manifest and the Service Manifest for the purpose of packaging and deploying the applications. An application in Service Fabric is a unit of deployment. An application can be deployed, upgraded, or even rolled back as a unit. The rollback usually occurs in case of a failure on upgrade and is automatically handled by the Service Fabric orchestrator to ensure system stability.

Application manifest, as the name suggests, is used to describe the application. It defines the list of services and the parameters required to deploy these services. Number of service instances being one of them.

Service manifest defines the components of a service. This includes data, code, and configuration. We will look deeper in these manifests in later sections of this book.