Why separate layers

Splitting the app to layers help maintain, decouple, and scale.

What is it

Most popular implementation of multi-tier architecture:

• presentation tier (client)
• logic tier (server)
• data tier (database)

Layers

Presentation Tier

Interacts with the user and the business layer

• UI and user interactions
• Presenting information to users and capturing input

Business Logic Tier

Store/retrieve Data Performs further processing Pass result to the presentation layer Respond to user requests