The data sync functionality is handled by Cloudant Sync. Cloudant Sync is a replication-protocol-compatible datastore for devices that don't want or need to run a full CouchDB instance. Cloudant replication functionality is used to synchronise data between the local datastore and a remote database, either a CouchDB instance or a Cloudant database. Many datastores can replicate with the same remote database, meaning that cross-device synchronisation is achieved by setting up replications from each device to the remote database.
