N-Tier / N-Layer Architecture (2024)

N-Tier and N-Layer areentirelydifferent concepts. People generallyuse this term during the design of the application architecture. N-Tier refers to the actual n system components of your application.On the other hand, N-Layers refer to the internal architecture of your component.

N-Tier architecture usually has atleast three separate logical parts, each located on separate physical server. Each tier is responsible for a specific functionality. Communication between tiers is typically asynchronous in order to support better scalability.N-Layers of application may reside on the same physical computer (same tier) and the components in each layer communicates with the components of other layer by well defined interfaces. Layered architecture focuses on the grouping of related functionality within an application into distinct layers that are stacked vertically on top of each other.

Pros and Cons of Tier and Layerd Architecture

• Tiers indicate a physical separation ofcomponents, which may mean differentassemblies on the sameserver or multiple servers.Layers refers to a logical separationof components, such as having distinct namespaces and classes for the DatabaseAccess Layer (DAL), Business Logic Layer (BLL)and User Interface Layer (UIL).
• Tiers could be on different machines, so they communicateby Value only – as serialized objects. Multi-layered design is suitable for small to mid-sizeprojects only.
• Tiers could be on different machines, so they communicateby Value only – as serialized objects. Layer communicates with each other either by Value or byReference.
• Tiered Architecture has all advantages of LayeredArchitecture +scalability as application will be deployed indifferent machines so load will be shared among the tiersand scalability will increase. Layered Architecture will improve readability and reusability

In Tier Architecture ASP.NET Web Servicesor .NET Remoting can be used in placeof Database Access Layer and BusinessLogic Layer. In .NET 3.0 & above WindowsCommunication Foundation (WCF) Servicescan be used, that will be great, it seems likeWeb Services but more powerful, secure andflexible than Web Services.