Consider using 4+1 Architecture view to describe architecture of your software.
Summary of the views is given below:
Development view: An implementation view from software developer perspective. UML Diagrams (such as package diagram) could be used to represent this view.
Logical view: It provides functional view describing functionality that the system provides to end-users. UML diagrams (such as class diagrams, and activity diagrams) could be used to represent the logical view.
Physical view: It reveals a system engineer's point of view. It is also referred as the deployment view. Deployment diagram could be employed to describe the view.
Process view: It captures the dynamic aspects (concurrency, runtime behavior, etc.) of the system. Activity diagrams are suitable for the view.
Scenarios: Scenarios (or use cases) describe sequences of interactions between objects and between processes.