Explain the TWO-Tier Architecture of SSAS? | MS-BI

?    SSAS uses both server and client components to supply OLAP and data mining functionality BI Applications.
?    The server component is implemented as a Microsoft Windows service. Each instance of Analysis Services implemented as a separate instance of the Windows service.
?    Clients communicate with Analysis Services using the standard the XMLA (XML For Analysis) , protocol for issuing commands and receiving responses, exposed as a web service.