New, as of AEM Communities 6.1, is the ability to use a common store for community content, also referred to as user generated content (UGC).
When community content is stored in a common store, all UGC is directly accessible for create, read, update, and delete (CRUD) operations from all AEM author and publish instances. Thus, with the common store approach, there is no need to synchronize UGC across AEM instances using reverse/forward replication, as was necessary in previous releases of AEM social communities.
There is a choice from several options for storing community content. All options implement a new interface through which UGC is accessed, the SocialResourceProvider API (SRP), but not all options provide a common store for UGC.
Understanding the characteristics of each option is crucial to the decision process for choosing the appropriate common store and underlying deployment.