A computer checks the database of user names and passwords for a match before granting access.

Answer:

The correct answer is option 'D', Database.

Explanation:

When a user tries to gain access to a computer system, they typically need to provide a username and password. These credentials are checked against a database that stores the usernames and their corresponding passwords. The computer system checks whether the provided username and password match the records in the database before granting access.

The database is an organized collection of data that is stored and accessed electronically. It is designed to efficiently manage and retrieve data. In this case, the database holds the user information, including usernames and passwords.

Importance of Database for User Authentication:

The use of a database for user authentication offers several advantages:

1. Security: Storing user information in a database ensures that it is protected from unauthorized access. The database can be secured with proper access controls and encryption to prevent data breaches.

2. Efficiency: By checking the username and password against a database, the authentication process can be performed quickly. The database can be indexed and optimized to provide fast retrieval of user information.

3. Scalability: As the number of users increases, the database can handle the growing amount of user information without significant performance degradation. The database can be designed to handle large volumes of data efficiently.

4. Centralized Management: Storing user information in a database allows for centralized management. User accounts can be easily created, modified, or deleted in the database, simplifying the administration process.

Conclusion:

In summary, a computer checks the database of user names and passwords for a match before granting access. The database stores the user information and is responsible for verifying the credentials provided by the user. This ensures the security, efficiency, scalability, and centralized management of user authentication.