The elementary unit of information is the bit,
which means the distinction
between exactly two states.
Such two states can for instance be
whether in a part of an electronic circuit
energy is flowing (bit=1) or not (bit=0).
Just like the power of moving electrons
can be employed to move motors, feed lights,
swing magnets and so on, it can also be used
to control the flow of electricity itself.
This is done with electronic switches which
consist of a tiny strip of semiconductor materials.
Their layers form a barrier, a strong resistor (bit=0),
unless when fed from the side (input) by electrons,
which then overloads the barrier to turn it into
a conductor, to allow the main flow of electrons
to be transmitted (bit=1) through this transistor.
With transistors (electronic switches), one can build
little electronic circuits that can turn bits on or off
and allow them to be read.
The computer's RAM (random access memory,
"random" here means "read or write anytime")
consists of zillions of these so-called flip-flop circuits,
packed as microscopic structures into a microchip,
much like biological tissue forms
the organs of a living being.
Other microphysics technologies allow bits to be
stored when the electric current is turned off,
such as hard disk drives, CD-RWs, DVDs, Flash
— and ROM (read-only memory).
ROM are bits "set in stone" to tell the computer
upon being switched on what to do to start up.
Learning Programming with Eas — the Tutorial by Molaskes
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