Division of the range of values of a wave into a finite number of subranges, each of which is represented by an assigned or quantized value within the subrange.

1. The restriction of an observable quantity, such as energy or angular momentum, associated with a physical system, such as an atom, molecule, or elementary particle, to a discrete set of values.

2. The transition from a description of a system of particles or fields in the classical approximation where canonically conjugate variables commute, to a description where these variables are treated as noncommuting operators; quantization (first definition) is a result of this procedure.

The restriction of a variable to a discrete number of possible values; thus the age of a person is usually quantized as a whole number of years.