Flip-flop (electronics)

[1] In electronics, flip-flops and latches are circuits with 2 stable states that can store state info – a bistable multivibrator, made to change state by signals used to 1+ control inputs and output its state (often along with its logical complement too). It's the basic storage element in sequential logic.
They're fundamental digital electronics systems' building blocks for computers, communications, and other systems types.