Statistical classifications provide a coherent, systematic and standardized context for structuring the production and dissemination of statistical data.
In its simplest form, a classification consists of a hierarchical structure of group and subgroup names with corresponding identifiers (numeric or alphanumeric codes). Classifications include group definitions (names, codes, and description of each group), as well as a presentation of the basic concepts and classification principles and criteria.
Statistical concepts are based on precise definitions that allow a shared understanding of the characteristics and aspects being measured.
For example, in the case of a statistical survey, concepts are used to define the subject matter of the survey and analysis, the statistical units to be described, or the population to be surveyed. These concepts refer to the general characteristics or attributes of a statistical unit or group of similar statistical units.