Learn in the textbookUnits of Information and the Digitization Process
DefinitionQuantization (量子化) is the step that fits each value taken by sampling to the closest of a set of levels decided in advance.
ExplanationThe number of levels depends on how many bits are used to represent one sample, and this number of bits is called the quantization bit depth (also called the encoding bit count). The gap from the original value that arises when rounding to a level is called the quantization error, and it gets smaller as the levels get finer.
AnalogyIt is like the difference between a bathroom scale that shows 0.1 kg steps and one that shows 1 kg steps: the finer the steps, the closer the reading is to the true value.
Memory hookThe kanji 量子 is the physics word for a quantum, the smallest step-like amount, which links to placing values onto separate marks on a scale.