What role does a Foreign Key (FK) play in a relational database?

A Foreign Key (FK) is a crucial concept in relational databases as it defines the relationship between tables. When one table's column (or set of columns) contains values that refer to the primary key in another table, it creates a linkage that establishes how the two tables interact with each other. This relationship allows for the normalization of data, minimizing redundancy and ensuring that related data is correctly associated across the database structure.

Understanding that a Foreign Key creates this relationship aids in structuring your data correctly so that queries can effectively join related records from different tables. It directly points to the table and column that form the linkage, illustrating how entities are connected, which is fundamental in maintaining a coherent database schema.

The other options may touch on aspects related to Foreign Keys, but they do not accurately define their primary role. For instance, while a Foreign Key does contribute to data integrity, it is not its primary function. The purpose is more specifically about establishing relationships rather than serving as a standalone data integrity feature or merely identifying primary keys. Additionally, stating that it serves as a table attribute is more about the nature of database design than defining the core function of a Foreign Key. Recognizing the Foreign Key's role in defining relationships is key to optimizing database design and query