Final answer:
A diode is the electrical component that allows current to flow in only one direction and operates similar to a check valve.
Step-by-step explanation:
A diode is the electrical component that allows current to flow in only one direction and operates similar to a check valve. Just like a check valve allows fluid to flow in only one direction, a diode allows current to flow in only one direction. When a diode is forward-biased, it allows current to pass through, but when it is reverse-biased, it blocks the current. This property makes diodes essential in circuits to control the direction of current flow.