Term Kind Topic What it is
Harvest and Yield concept CAP & PACELC A refinement of CAP that treats availability as a continuum — yield is the fraction of requests answered, harvest is the fraction of data reflected in an answer.
PACELC concept CAP & PACELC An extension of CAP stating that during a partition you trade availability against consistency, and else — in normal operation — you trade latency against consistency.
Partition Tolerance concept CAP & PACELC The ability to keep operating when the network drops or delays messages between nodes — not a choice, but a property of any system spanning more than one machine.