What is N-Tier Architecture?
N-Tier Architecture divides a system into separate deployment tiers, usually running on different servers or groups of servers and communicating over a network. A common arrangement has three tiers: web, business and data.
The key distinction is that a layer separates code responsibilities, while a tier separates deployment locations. One deployment tier can contain several code layers. Creating three folders within an application does not make it a three-tier system.
