I've been struggling to get my head around voltage and amps - specifically after I bought a device that wanted 5V and 2A supply, but I was only giving it 1.6A I found the machine would fail (and reboot). The lack of amperage meant it wasn't able to supply the entire board.
Just the image from this post was enough to make it click in my head 👍
VOLTAGE is like the pressure that pushes water through the hose. It is measured in volts (V).
CURRENT is like the diameter of the hose. The wider it is, the more water will flow through. It is measured in amps (I or A).
RESISTANCE is like sand in the hose that slows down the water flow. It is measured in ohms (R or Ω).