What is a bistable multivibrator?

A bistable multivibrator is an electronic circuit that has two stable states. It remains in one of these states indefinitely until an external trigger pulse forces it to switch to the other state. In the realm of digital logic and computer electronics, this circuit is universally known as a flip-flop. Other multivibrator types serve different functions. For example, an "astable" multivibrator has no stable states and acts as a free-running oscillator or clock. AND and OR gates are purely combinational logic circuits, meaning their outputs depend solely on their present inputs, unlike a flip-flop which retains memory of its previous state.