What are the two elements that form the primary key in a database?

A primary key in a database is formed from two main elements:

1. Uniqueness — a value or set of values that uniquely identify each record in the table.
2. Immutability — the primary key values should not change after the record is created.

Most often, the primary key consists of a single column (e.g., ID), but it can be composite, combining two or more columns to ensure uniqueness.