Electricity is the flow of electrons from one place
to another. Electrons can flow through any
material, but does so more easily in some than in
others. How easily it flows is called resistance.
The resistance of a material is measured in Ohms.
Matter can be broken down into:
Conductors: electrons flow easily. Low resistance.
Semi-conductors: electron can be made to flow
under certain circumstances. Variable resistance
according to formulation and circuit conditions.
Insulator: electrons flow with great difficulty. High
Since electrons are very small, as a practical
matter they are usually measured in very large
numbers. A Coulomb is 6.24 x 1018 electrons.
However, electricians are mostly interested in
electrons in motion. The flow of electrons is
called current, and is measured in AMPS. One amp is equal to a flow of one coulomb per
second through a wire.