What are Shift Registers - Sequential Logic Circuit?

The Shift registers are a type of sequential logic circuit that mainly for storage of digital data and they are a group of flip-flops connected in a chain so that the output from one flip-flop becomes the input of the next flip-flop the most of the registers possess no characteristic internal sequence of states. With all the flip-flops are driven by a common clock and all are set or reset simultaneously.

There are different kinds of shift registers those are Serial In - Serial Out, Serial In - Parallel Out, Parallel In - Serial Out, Parallel In - Parallel Out and bidirectional shift registers.