Practical takeaway
Metals such as copper have many free electrons that can move through the material. Apply a voltage difference and those electrons begin to move in a directed way through the conductor. That flow of electrons is electric current.
Electricity & Electronics
What Makes Electricity Flow?
See the practical model of how electrons move through a metal conductor when a voltage difference is applied.
TECHNICIAN FOUNDATION1 of 16
Technician exam focus
The Technician pool uses these ideas directly: metals are good conductors because they have many free electrons; current is the flow of electrons in an electric circuit; and a difference in voltage causes electron flow. Current is measured in amperes.
Start with the useful model
Metal conductors have many free electrons.
That is one reason metals such as copper are good electrical conductors. Those free electrons can move through the material.
Voltage provides the electrical push.
A difference in voltage causes electron flow. Voltage is measured in volts. You may also hear the source of that electrical push described as electromotive force (EMF).
Electron flow is electric current.
When free electrons move through a metal conductor in a directed way, that flow is called current. Current is measured in amperes, or amps.
That practical model is enough to get started.
For building and troubleshooting, remember the useful chain: a conductor provides a path, voltage provides the push, electrons flow, and resistance opposes that flow.
STEMulation
Apply voltage and watch electron flow
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+The blue dots represent free electrons already in the metal conductor.
What the blue dots mean: each blue dot represents a free electron. The movement is deliberately exaggerated so it is easy to see.