N-Layer architecture vs N-tiered architecture

First of all we cant differentiate between N-Tier & N-Layer, becuase its entirely a different concepts.
N-Tier - Deals with where your code and processes run, like where your code resides, where your web server runs, where your database server runs. Tiers should be always minimized, since it will affect the performance, security, scalablity like that.
 
N-Layer - Deals with how your code is layered, like presentation layer, business logic layer, data access layer. Layers should be always loosely coupled, if it so code impact will be very minimal for doing future enhancements
 
Mark it as accepted answer, if this post really helped you.