What is the main function of a Foreign Key in a database?

The main function of a Foreign Key in a database is to establish a relationship between tables. A Foreign Key is a column or a group of columns in one table that refers to the primary key in another table. This relationship ensures that data remains connected across multiple tables, creating a structured and relational database design.

When a Foreign Key is used, it creates a linkage between two tables, allowing for more complex queries that can retrieve related data from both tables. This is essential for maintaining the relational aspect of a database, where the relationships between the data elements are as important as the data itself.

While the other options do have valid aspects in the context of databases, they do not capture the primary role of a Foreign Key as effectively. For instance, uniquely identifying a record typically relates to a primary key, while enforcing data integrity and storing large objects are relevant but secondary considerations in terms of the primary purpose of a Foreign Key.