What are the Server roles in a Sitecore Commerce Deployment?

Sitecore

Content Management Server

A Sitecore instance used for authoring content before publishing it to production. For example, a master database.

Content Delivery Server

A Sitecore instance used for serving up published content. For example, a web database.

Search Server

A server used to host search queries. This is only used with Solr or other search solutions that are not hosted on the same server as Sitecore.

Processing Server

Performs reducing functions on experience data, which then stores the data in the reporting database.

Reporting Service

Handles queries against the Sitecore xDB aggregated data.

Commerce Server

Business Management server

A set of web services used by BizTalk and the desktop business tools for managing Commerce Server sub system data. For example, catalog, profiles, orders, and marketing

Commerce Server Staging

A Windows service for moving Commerce Server subsystem data between environments.

SCpbMD

Transaction Service

A service used to talk to Dynamics AX for cart, order, price, and profile data.

Routing Service

Used to map data from the Dynamics AX Channel database into the Commerce Server Catalog subsystem

Microsoft Dynamics AX

Dynamics AX AOS Server

The Microsoft Dynamics AX Application Object Server (AOS) shares application objects and information to increase application performance.

General

SQL Server

Used to store Sitecore and Commerce Server databases.

MongoDB

Used to store Sitecore xDB data.

BizTalk

Used for EAI to ETL data between Commerce Server and LOB systems.