In storage architectures, what term refers to a distinct level of storage defined by performance and cost?

• A. Tier
• B. Layer
• C. Subsystem
• D. Segment

Answer: (A)

The idea being tested is how storage is organized by performance and cost. A tier is a distinct level of storage that has its own speed, latency, throughput, capacity, and price. In practice, storage systems use tiers to place data on appropriate media: fast, expensive media like SSDs for data that’s accessed often (hot data), and slower, cheaper media like HDDs or archival options for data that’s accessed less frequently (cold data). This arrangement lets the system balance performance with cost, often moving data up or down between tiers automatically through tiering policies. The other terms don’t convey a level defined by performance and cost in storage architectures: a layer is a part of a stack or abstraction, a subsystem is a modular group of components, and a segment is a portion of data or a processing unit rather than a defined performance-cost level.