Region of the absorption/transmission spectrum in which the absorbance/transmission passes through a maximum/minimum.
Note: The use of the term "spectral band" implies a wider region of the spectrum than "spectral line" (see
spectral line of an atom).
Source:
PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 673 (https://doi.org/10.1515/pac-2019-0203)