Can anybody tell me what is the difference between N-Layer and N-Tier architecture.I know 3-layer architecture has 3 layers: UI, Business Logic Layer(BLL) and Data Logic Layer(Dll)
But now, my question is what is N-Tier and N-Layer and what is the difference between these.
Also how do these interact with one layer to another in respect to C#?
On
It has been my general understanding that n-layer represents the logic separation of the application into logical groupings. While an n-tier application is the same thing but with PHYSICAL separation. The two do go hand in hand -- though you could take a 3-layer application and have a 4-tier deployment with UI on the client / Business Layer on one server / DataAccess Layer on a third server / and the Data on a fourth server.
So think of your layers as POTENTIAL ways to improve (or destroy) performance by being able to break out portions of the application and deploy them to different physical devices. However since they are logic they can also all be on one machine. This includes having everything on a single users' machine.
Now until I got my current job my first thought would be to say "why would anyone run an n-layer application on a single machine. But if you have components of an application that have Special Access Program clearance by the department of defense, there are only two ways to accomplish that. The first is to have everything on a machine not connected to any outside network anywhere. The second is to only be connected on a private D.O.D. network that only Top Secret and higher data can move.
In my opinion, the definitions of "layer" and "tier" are the same and can be used as synonyms.