tier

Tier generally refers to a level or layer within a system of ordered levels. The term originates from Old French tier, meaning a row or layer, and has been applied to various contexts where items are arranged in successive levels.

In common use, tiers denote horizontal levels arranged one above another, such as seating rows in theatres or stadiums, or steps in a structure. In architecture and design, tiers can describe stacked platforms, shelves, or elevated surfaces that create a stepped arrangement.

In organization and classification, tiers describe hierarchical ranking or categorization. A tiered system may define levels of access, priority, or quality, with higher tiers offering more features or privileges. Examples include tiered pricing models (basic, standard, premium), tiered service levels in customer support, and tiered membership programs.

In infrastructure and technology, tiering appears in storage and data management. Tiered storage assigns data to different storage tiers (hot, warm, cold) based on access frequency, cost, and performance requirements. Tiering is also used in software architecture to describe layered components or services.

Additionally, tier appears in physical design to indicate raised platforms with multiple horizontal surfaces, such as tiered trays or tiered seating. It is also common in competitive contexts to categorize items or players into tiers, for example a tier list. See also: tiered pricing, tiers of service, theater seating.