D365 Cloud POS (CPOS) Simplified Architecture

Above diagram is showing CPOS simplified architecture with its main components:

POS Client 1/2 with Shared Hardware Stations:
• On left side we can see two POS machines which are running CPOS with shared hardware station installed in separate machine.
• Actually CPOS supports shared hardware station but we can setup on each machine separately and make it local sharing. 
• Different peripheral devices are connected with hardware station like printer, scanner, MSR etc.

CPOS Hosted on IIS Cloud/Local:
• On right side we can see that CPOS website hosted on IIS (Azure Cloud) which can be browsed from everywhere.
• CPOS website can be hosted on local IIS in case of RSSU (Retail Store Scale Unit) which can be browsed over an organization intranet.

Retail Server Hosted Cloud/Local:
• On right side we can see retail server hosted on IIS (Azure Cloud) which is providing data to CPOS. CPOS is calling Retail server for performing CRUD operation on database.
• Retail Server can be hosted on local IIS in case of RSSU (Retail Store Scale Unit) which can be browsed over an organization intranet.
• Retail Server is comprised of a set of APIs which can be accessed in order to perform operations through POS or online stores.
• It Consists of ODATA API due to which retail server can be connected to any application and supports advance authorization and authentication.
• Retail Server uses CRT for handling data from database. Retail server just holds ODATA request from client and parse it into CRT objects and pass to CRT and then CRT query database.

Commerce Runtime (CRT):
• CRT is part of Retail Server and also hosted with retail server on machine.
• Commerce Runtime is the core engine which performs all the core business operations and contains the business logic for retail.
• It is comprised of multiple layers that are data access layer, workflow layer, service layer and API.

Database (Channel Database / Store Database / Brick and Mortar Database):
• Channel database has multiple names wrote in above heading.
• It will save all data of POS/Online Store or any other client which is calling by Retail Server.
• Channel database will be called from CRT.