Final answer:
Quantization refers to physical entities existing in discrete values rather than a continuum. It's a fundamental concept in quantum physics, evidenced by phenomena like the ultraviolet catastrophe, leading to the development of quantum mechanics.
Step-by-step explanation:
Quantization is the concept that the natural world is quantized rather than continuously smooth. This means that physical entities such as atoms, molecules, and fundamental charges exist only in certain discrete values and do not have a continuous range of values. In quantum physics, we observe that energy, which is a crucial physical entity, is quantized. Energy can exist only in specific packets or bundles, and like the steps you take when climbing a staircase, energy takes on discrete values rather than allowing for a continuum of values. This idea was pivotal in resolving the ultraviolet catastrophe, a problem which suggested that blackbodies (idealized objects that absorb and radiate energy) should emit infinite amounts of high-frequency energy, which they do not. Instead, Planck proposed that energy levels within atoms and molecules are quantized, which led to the development of quantum mechanics, a subfield of physics essential to our understanding of the micro-world.
An example of a physical entity that is not quantized and is continuous might be temperature in a macroscopic sense, which can vary continuously without discrete steps.