Classificatory kinship systems, as defined by Lewis Henry Morgan, put people into society-wide kinship

Kinship

Kinship is a relationship between any entities that share a genealogical origin, through either biological, cultural, or historical descent. And descent groups, lineages, etc. are treated in their own subsections....

 classes on the basis of abstract relationship rules. These may have to do with genealogical

Genealogy

Genealogy is the study of families and the tracing of their lineages and history. Genealogists use oral traditions, historical records, genetic analysis, and other records to obtain information about a family and to demonstrate kinship and pedigrees of its members...

 relations locally (e.g., son to father, daughter to mother, daughter to father) but the classes bear no overall relation to genetic closeness. If a total stranger marries into the society, for example, they may simply be placed in the appropriate class opposite to their spouse.
It uses kinship terms that merge or equate relatives who are genealogically distinct from one another. Here, the same term is used for different kin.

The Dravidian kinship-term

Kinship terminology

Kinship terminology refers to the various systems used in languages to refer to the persons to whom an individual is related through kinship. Different societies classify kinship relations differently and therefore use different systems of kinship terminology - for example some languages...

system, discovered in 1964, is an example of a classificatory kin-term logic.