Three

In software engineering, this IBM-defined model separates applications into the presentation tier (user interface), application tier (logic), and data tier (database) to improve security and scalability [27].

This partial meltdown at a Pennsylvania nuclear plant remains the most serious accident in U.S. commercial nuclear power history [16]. Investigative reports on the event led to permanent changes in how the Nuclear Regulatory Commission (NRC) handles safety and worker training [34]. 2. Scientific & Conceptual Triads In software engineering

The number three is often used to categorize information for clarity and efficiency: application tier (logic)

Science and technology frequently utilize "three-tier" structures to manage complexity and ensure stability: In software engineering