Analog
Analog is a term used in computer-related discussions to describe the lowest conceptual level at which computer components can be examined. (Obviously, in actuality, all computers are 'analog' at their lowest level, since they are built out of electrical circuits.)
It also has a main meaning of referring to things which have infinitely variable values; i.e. the values have to be measured in real numbers, not integers (which is the case with most digital devices).
Things such as voltages, currents, resistors and transistors are both:
- the elements used at the lowest conceptual level; and
- things which have infinitely variable values.
Note particularly that voltages are not binary, but can take any value; this is important in topics such as meta-stability.
Analog computers
The term (sometimes spelled in the old-fashioned form analogue in this usage) is also used to name computing devices, analog computers, in which the fundamental, basic data items have infinitely variable values (voltages, currents etc) - i.e. the meaning above - instead of the limited, discrete, values used in digital computing devices.
