In SQL (Structured Query Language), the term cardinality refers to the uniqueness of data values contained in a particular column (attribute) of a database table.
[1] When dealing with columnar value sets, there are three types of cardinality: high-cardinality, normal-cardinality, and low-cardinality.
High-cardinality column values are typically identification numbers, email addresses, or user names.
Normal-cardinality column values are typically names, street addresses, or vehicle types.
Since there is a variety of possible values held in this column, its cardinality type would be referred to as normal-cardinality.