Q. What is Service Fabric?
A. Service Fabric is a distributed platform that started in Azure and is also available to run on-premises. It is used to run many of the services in Azure and also components in Windows Server 2016. It is a technology that enables multiple nodes to jointly deliver a service in a highly available and scalable manner as part of a Service Fabric cluster. No shared storage is required, instead all the nodes replicate state synchronously between nodes which ensures all nodes have an up-to-date copy of the state of the service the cluster offers. Where persistent state is required an external storage service is used such as Azure Storage or Azure SQL Database.
Service Fabric is designed to run todays new breed of microservices that are quickly created and deleted as needs require. A microservice approach breaks a service into small parts that can be distributed and scaled independently. Often you will hear the term actors which are instances of microservices.
For more detailed documentation see https://azure.microsoft.com/en-us/documentation/articles/service-fabric-overview/.