3 Layer Architecture

A three-layer architecture is a common software design pattern that divides an application into three distinct layers.
A layer is a logically separated part of the application.

Presentation Layer - Handles user clicks, HTTP requests, and provides the API for user interaction.

Domain Layer - Domain(business) logic of the application. This layer handles data and converts it to other data structures.

Data Access Layer - Provides access to the database and manages transactions.

@startuml component "Presentation Layer" { } component "Domain Layer" { } component "Data Access Layer" { }

"Presentation Layer" --> "Domain Layer" "Domain Layer" --> "Data Access Layer"

@enduml

Note

Presentation Layer can initiate calls to code from Domain Layer, not vice versa. Domain Layer can initiate calls to code from Data Access Layer, not vice versa.