Minecraft wiki entry for Memory, associated text: A D ("data") flip-flop or latch has two inputs: The data line D, and the "clock" input C. When triggered by C, the circuits set their output (Q) to D, then hold that output state between triggers. The latch form, a "gated D latch", is level triggered. It can be high- or low-triggered; either way, while the clock is in the trigger state, the output will change to match D. When the clock is in the other state, the latch will hold its current state until triggered again. A D flip-flop is edge triggered; it sets the output to D only when its clock input changes from "off" to "on" (rising edge) or vice versa (falling edge), according to the circuit. An edge trigger can turn a gated D latch into a D flip-flop.