Source : https://technet.microsoft.com/en-us/library/dd362112.aspx
The following diagram provides a high-level overview of the system architecture of Microsoft Dynamics AX. This diagram does not depict the system topology or physical infrastructure that are required for the deployment. Your infrastructure can consist of many Microsoft Dynamics AX components, and these components can be installed on either a single physical server or multiple physical servers. For factors that you must consider when you plan a deployment infrastructure, see Plan system topology. For detailed information about Microsoft Dynamics AX components, see Component architecture. For the current hardware and software requirements for Microsoft Dynamics AX, see the system requirements document that is available from the Microsoft Download Center.