natural key

A candidate key that describes the subject of the table, such as the name or serial number. The field meets the requirements for a primary key and can be used to uniquely identify the record.

network

A group of computers that are connected to each other for the purpose of communication.

normal forms

The criterion by which the tables in a database are measured with respect to adherence to relational data modeling principles.

null

An unknown; the absence of data without knowing if there is valid data as contrasted with an Empty String or Zero Length String (ZLS).