replication peer (or just peer, in this context): a ZFS Storage Appliance that has been configured as a replication source or target.
replication source (or just source): an ZFSSA peer containing data to be replicated to another ZFSSA peer (the target). Individual ZFSSAs can act as both a source and a target, but are only one of these in the context of a particular replication action.
replication target (or just target): an ZFSSA peer that will receive and store data replicated from another ZFSSA peer (the source). This term also refers to a configuration object on the ZFSSA that enables it to replicate to another ZFSSA.
replication group (or just group): the set of datasets (exactly one project and some number of shares) which are replicated as a unit. See Project-level vs. Share-level Replication .
replication action (or just action): a configuration object on a source ZFSSA specifying a project or share, a target ZFSSA, and policy options (including how often to send updates, whether to encrypt data on the wire, etc.).
package: the target-side analog of an action; the configuration object on the target ZFSSA that manages the data replicated as part of a particular action from a particular source. Each action on a source ZFSSA is associated with exactly one package on a target ZFSSA and vice versa. Loss of either object will require creating a new action/package pair (and a full replication update).
full sync (or full update): a replication operation that sends the entire contents of a project and some of its shares.
incremental update: a replication operation that sends only the differences in a project and its shares since the previous update (whether that one was full or incremental).