Here is the first one… 😉
Each layer represents the distribution of an attribute on the surface of the 3D model. Layers can hold two kinds of attributes: Numeric scalar values or Labels/categories.
Scalar attributes are useful to store numeric values such as measures, classifications, tagging, etc. On the other hand, Labels or Categories attributes hold an user-defined set of data fields including different kinds of data: strings, numeric values, dates or files.