How Rows, Columns, and Primary Keys Work
The relational model represents data as a table of rows and columns, called a relation. Each row is a record — one complete unit of data — and each column is an attribute, a single field of data. The primary key is the column that uniquely identifies each row.
GOAL
Explain the roles of rows, columns, and the primary key in the relational model.
In this table, which column uniquely identifies each row as the primary key?