JK Flip-Flop Definition/Meaning:
A clocked flip-flop that has two inputs, J (set) and K (reset), and
two outputs Q and Q. Qn represents the state of the Q output prior to
the current active transition of the clock. The ambiguous condition of J and K
both being true, logic 1, causes the device to "toggle", i.e. change to the
complementary logic state, on active transitions of the clock signal. The JK
flip-flop is the most useful type of flip-flop and is available as a standard
in-tegrated-circuit package. See also flip-flop.