A backward diode is a special kind of electronic component that can allow electric currents to flow easily in both directions, unlike most other components which only allow currents to flow in one direction.
Think of it like a one-way street where cars can only drive in one direction. A normal diode would be like a street with a big wall in the middle, stopping cars from crossing. However, a backward diode would be like a street without the wall, letting cars drive in both directions.
When electricity flows through a backward diode in one direction, it acts like a regular diode and stops the flow of current unless a certain threshold voltage is exceeded. But when electricity flows in the opposite direction, it becomes conductive and allows current to flow much more easily than a regular diode.
This unique behavior makes backward diodes useful in some electronic circuits where the current needs to flow in both directions, like in automatic voltage regulators or oscillators.