Multitier architectureIn software engineering, multitier architecture (often referred to as n-tier architecture) is a client–server architecture in which presentation, application processing and data management functions are physically separated. The most widespread use of multitier architecture is the three-tier architecture. N-tier application architecture provides a model by which developers can create flexible and reusable applications. By segregating an application into tiers, developers acquire the option of modifying or adding a specific tier, instead of reworking the entire application.
Event-driven architectureEvent-driven architecture (EDA) is a software architecture paradigm promoting the production, detection, consumption of, and reaction to events. An event can be defined as "a significant change in state". For example, when a consumer purchases a car, the car's state changes from "for sale" to "sold". A car dealer's system architecture may treat this state change as an event whose occurrence can be made known to other applications within the architecture.
Architecture description languageArchitecture description languages (ADLs) are used in several disciplines: system engineering, software engineering, and enterprise modelling and engineering. The system engineering community uses an architecture description language as a language and/or a conceptual model to describe and represent system architectures. The software engineering community uses an architecture description language as a computer language to create a description of a software architecture.