What is the main function of a primary key in a database?

The main function of a primary key in a database is to uniquely identify each record. This unique identification is crucial because it ensures that no two records in a table can have the same primary key value. This uniqueness allows for accurate data retrieval and manipulation, making it easier to locate specific entries within a database.

A primary key acts as a cornerstone for maintaining data integrity. When each record is uniquely identifiable, it helps in enforcing relationships between various tables in a relational database, ensuring that there is a reliable way to reference records without ambiguity. Thus, the correct answer highlights the essential role of primary keys in the organization and management of database records.