What is information about data called?

A primary key is a unique identifier for a record in a database table.

Imagine a table of students. Each student has a unique student ID number. This student ID would be the primary key because it uniquely identifies each student record.

Key characteristics of a primary key:

Unique: No two records can have the same primary key value.

Not Null: Every record must have a primary key value.

Minimal: It should contain only the necessary columns to uniquely identify a record.

Purpose:

To efficiently locate specific records.

To establish relationships between tables (foreign keys).

To maintain data integrity.

By using primary keys, a database system can quickly find, update, or delete specific records without confusion or errors.