What is the purpose of a procedure in a relational database system?

In a relational database system, a procedure, often referred to as a stored procedure, serves as a subroutine that can be invoked by applications or users to perform a specific task or set of tasks. This encapsulation allows for reusable code that can handle complex operations, such as data manipulation, validation, and business logic implementation, without requiring the application to directly code those operations multiple times.

Stored procedures offer several advantages, including improved performance through precompilation, enhanced security by restricting direct access to tables, and the ability to maintain consistency across various applications since the logic remains centralized within the database. By serving as a subroutine, they streamline database operations and promote better management of database interactions.

The other options represent different functionalities in a database system. While user permissions deal with access control, a database schema pertains to the structure of the database itself, and automated backups focus on data preservation. Each of these serves a distinct purpose, but they do not capture the essence of what a procedure is designed to do within the context of application development and data operations.