persona: a single “facet” of a physical person as seen by the user, such as a contact for them on a particular IM service, their profile on a social networking site or the user's address book entry for the person.
individual: a collection of one or more personas which relate to the same physical person.
user: the physical person who owns the currently logged in user account on the computer.
client: an application (or library) which uses libfolks.
link (verb): to “connect” two personas (which should relate to the same physical person) in a non-destructive manner to form an individual.
unlink: to break the links between the personas forming an individual so that they are no longer aggregated into that individual.
aggregation: the process performed by libfolks which takes all the implicit and explicit links between personas and uses them to form individuals which (should) uniquely represent physical people known by the user.
linked individual: an individual which contains more than one persona.
singleton individual: an individual which contains only one persona (i.e. that persona has no implicit or explicit links).
implicit link: a link between personas which wasn't explicitly created by the user; it was inferred by libfolks from trusted data which is shared by the personas in question.
explicit link: a link between personas which was explicitly created by the user.

