Define the Binary Counting - Counters?

The Binary counter is capable to be constructed from J-K flip-flops by taking the output of one cell to the clock input of the next The J and K inputs of each flip-flop are set to 1 to produce a toggle at each cycle of the clock input and for each two toggles of the first cell a toggle is produced in the second cell and so on down to the fourth cell this produces a binary number equal to the number of cycles of the input clock signal.

And this device is sometimes called as a "ripple through" counter and the same device is useful as a frequency divider.