What is Software Architecture?
High Level
Structure
Layers
Components
Relationships

System
Sub Systems
Layers
Components
Classes
Data and Methods

Messy vs Clean Architecture
Sphagetti vs Lasagna

Bad Architecture is Complex, Incoherent, Rigid, Brittle, Untestable and Unmaintenable

Good Architecture is Simple, Understandable, Flexible, Emergent, Testable & Maintainable

Clean Architecture is designed for the inhabitants of the architecture not for the architect or machine. It is about essentials and not details.

Donald Kanooth