In the Beer Lambert Law (equation 3) the term IT/Io is called transmittance. This form of spectroscopy has a setup similar to the one used for Absorption. Reflectance spectroscopy is the study of light as a function of wavelength that has been reflected or scattered from a solid, liquid, or gas.
Definition of metadata: Data that serves to provide context or additional information about other data. For example, information about the title, subject, author, typeface, enhancements, and size of the data file of a ...
Metadata, usually defined as data about data, is used to describe an object (digital or otherwise), its relationships with other objects, and how the object has been and should be treated over time. Metadata allows users to locate and evaluate data without each person having to discover it anew with every use.