Question

what is the primary key?

Answer 1

A primary key, also called a primary keyword, is a key in a relational database that is unique for each record. It is a unique identifier, such as a driver license number, telephone number (including area code), or vehicle identification number (VIN). A relational database must always have one and only one primary key.

Answer 2

A field or a combination of fields that uniquely identify a record in a table is called a primary key.