What is a characteristic of a Foreign Key in a relational database?

A Foreign Key serves a crucial role in establishing and enforcing relationships between tables in a relational database. By creating a link between two tables—specifically, linking a column in one table to the primary key in another—it allows for the representation of relationships that mirror real-world connections. For example, if one table stores customer information and another stores order details, the Foreign Key can be used to link the orders to the respective customers by referencing the customer's unique identifier from the customer table.

While unique identifiers are indeed provided by primary keys, a Foreign Key does not itself uniquely identify a record within its own table; rather, it helps refer to a unique record in another table. Similarly, while combining datasets can occur as a result of using Foreign Keys during operations such as joins, the primary characteristic that highlights the function of a Foreign Key is its ability to create relationships between tables. A Foreign Key does not inherently force data redundancy; redundancy is generally a consequence of poor database design or normalization issues. Therefore, the characteristic of a Foreign Key that underscores its purpose is its function in allowing for table relationships.