This diagram shows how the Linked Server works.The client-tier is a client application, might be a java program or a .Net Program that is communicating with our Server-tier which is the SQL Server Database. On the Server-tier we have a OLE DB which stands for Object Linking and Embedded Database, OLE DB is microsoft's standardize way in connecting with multiple datasources, through OLE DB we can now communicate with Oracle Databases, ODBC, MS Access, MS SQL Server, etc. The way OLE DB communicates with the different kind of DB Server is through OLE DB Providers.
