"s· Registers, formed from a collection of flip-flops, are used to store or manipulate data or both a Input and output function associated with registers include D Parallel input/ Parallel output a Serial input serial output a Parallel input Serial output a Serial input parallel output◼ Registers, formed from a collection of flip-flops, are used to store or manipulate data or both. ◼ Input and output function associated with registers include Parallel input / Parallel output Serial input / Serial output Parallel input / Serial output Serial input / parallel output