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 that also describes the normal case — if Partitioned choose Availability or Consistency, Else choose Latency or 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.