Final answer:
Quantum mechanics is a branch of physics that deals with the quantization of physical entities such as energy and angular momentum. It explains the orderliness and structure of the physical universe at the subatomic level.
Step-by-step explanation:
Quantum mechanics, a branch of physics, deals with small objects and the quantization of various entities, including energy and angular momentum. It explains the orderliness and structure of the physical universe at the subatomic level. In quantum mechanics, physical characteristics such as energy, charge, and angular momentum are quantized, meaning they appear only in certain discrete values and do not have every conceivable value. This quantization is of utmost importance in understanding the nature and dynamics of the submicroscopic world.