What Is The Difference Between Voltage, Current And Resistance?

I`ve had a physics question from a parent:
"My daughter is struggling with physics. Can you explain the difference between voltage, current and resistance?"

Imagine a water pump.
It is pumping water into a hosepipe.
The hosepipe circles back to the pump`s inlet. ;

So the water is travelling round and round the pipe in a large circle.

The pump is like a battery providing VOLTAGE (or pressure), the water is the CURRENT (or flow), running around the pipe.

Now imagine you pinch the hose halfway along its length. You are making it harder for the water to get through.
You have provided RESISTANCE!

The water inside the pipe, travelling TOWARDS your pinch will be at HIGHER pressure.
The water inside the pipe, travelling AWAY FROM your pinch will be at LOWER pressure.
The difference between the two pressures is another VOLTAGE!

So the pump is providing a supply of voltage to drive the current and you are creating a mini-voltage by creating a ;

RESISTANCE (partial blockage).

How can the pump be a voltage? Easy - the pressure at its output is greater than the pressure at its input.

Summary:

Voltage is pressure.

Current is flow.

Resistance fights against flow.

Often students ask: Hold on, why is current measured in Amperes or Amps but its symbol is "I"?
Because Ampere was the scientist who worked all of this out. He was using the French word for "intensity" so we label current as "I" but the unit is "Amps".

You`ll notice the terms "voltage" and "potential difference" - they are the same thing.