A diode is a device which allows the current to move in one direction.
The p-n junction diode when it is connected to a battery is called biasing.
If the positive terminal of the battery is connected to p type of a semiconductor it is called forward biasing and the negative terminal of the battery is connected to p-type of a battery, it is called reverse biasing.
In the forward bias, current flows through the diode whereas in reverse bias current will not flow.
Since, the forward bias conducts current with low resistance, it refers to the flow of electrons through the diode.
Hence, the diode in forward bias is equal to the flow of electrons through them or turned on switch.