A column or combination of columns that uniquely identifies each row in the table is called the _________ of the table.

The column or combination of columns that uniquely identifies each row in a table is called the Primary Key of the table.

In relational database design, a primary key serves as a unique identifier for a record in a table, ensuring that no two rows have the same key value. This is essential for maintaining data integrity and facilitating efficient data retrieval. A primary key must contain unique values and cannot contain NULL values. When a primary key is defined, it helps establish relationships between different tables in a database by allowing foreign keys to reference the primary key, enhancing data organization and relational integrity. Thus, the primary key is a fundamental concept in database management systems, ensuring that each entry in a table can be accurately identified and accessed.