ref: dimensional analysis
Tracking quantities by their units.
For example, we can ask whether an inch is more or less than a centimeter, as there is a conversion:
cm = in *2.54 (cm/in)
but not whether a centimeter is more or less than an hour, as the units don't convert.
Type-checking in languages like C++ is an implementation of this idea, in which quantities perforce declare units.
See: [https://en.wikipedia.org/wiki/Dimensional_analysis (link)]
nedwaves.com 2017