What does a two-tier model primarily rely on?

A two-tier model primarily relies on a client-server architecture where the client application communicates directly with the database server to retrieve and manipulate data. In this architecture, the client handles the presentation layer and user interface, while the server is responsible for data storage and processing. This division allows for efficient communication, as the client can send requests to the server and receive responses without unnecessary complexity.

This model is simpler than multi-tier architecture, which involves additional layers such as business logic or application servers. The two-tier setup is commonly used in smaller applications or environments where direct interaction with a database is sufficient and can streamline development and performance for certain applications.

The other options do not accurately reflect the primary reliance of a two-tier model. While cloud services, distributed file systems, or local-only applications each have their respective frameworks, they do not encapsulate the fundamental principles of a two-tier client-server architecture.