Holographic consensus is the concept of identifying a group's consensus view without requiring a high participation rate in the consensus. In other words, holographic consensus refers to techniques for making decisions that represent an entire group accurately without requiring as many individuals from that group to participate as might typically be required.
Holographic consensus is important for governance because it addresses what we call the scale problem: the tradeoff between scalability and representativity of decision-making. That is to say that the faster a governance system makes decisions, the more difficult it is for those decisions to accurately represent the system's constituents.
While the phrase refers to any technique for accomplishing this, DAOstack has implemented one particular algorithm for DAOs, which we call the Genesis Protocol. This protocol is the basis of our first holographic-consensus-enabled voting machine DAOs.