General
Also called NTier Pattern
Layers are closed
When a request comes in to any give layer, that request must flow through each layer in order to get to the one below it.
Layers of isolation
If I make a change to one of the layers, I only have to update the contract with the layer below and no other layers. Components are bound to a specific layer
Examples of typical layers
- Presentation Layer
- Business Layer
- Services Layer
- Persistence Layer
- Database Layer
