N-Tier Vs. Multi-Layered Architecture

Last week I was invited to assist Final Year Project Coordinator at University of Karachi to take viva for final year projects. So I observed one thing that students do not have clear picture between N-tier architecture and multi-layered architecture. So here I write few lines for them, hope that this will improve their understanding.

Layered architecture refers to logical distribution/separation of components like, a rough example will be, separate DLLs for Business Logic Layer(BLL) or Data Access Layer(DAL).

N-Tier refers to physical separation of components either on same machine or across different machines. For example, We have 3-tier architecture with UI on ASP.NET, BLL as WCF service on different server and DAL as WCF service on different layer. UI communicates with BLL and BLL with DAL. Even when there are multiple processes on single machine interaction through some means, let’s say services, it is said to be N-tier architecture.

Hope this will give you better idea. Don’t forget to live it 🙂

Have a good day!