Siebel Enterprise Integration Manager (EIM) is a server component in the Siebel eAI component group that transfers data between the Siebel database and other corporate data sources. This exchange of information is accomplished through intermediary tables called EIM tables. (In earlier releases, EIM tables were known as interface tables.) The EIM tables act as a staging area between the Siebel application database and other data sources.

EIM is your primary method of loading mass quantities of data into the Siebel database. You should use EIM to perform bulk imports, updates, merges, and deletes of data. Examples of each of the main EIM functions (import, export, update, and delete) are provided in .EIM Functions..
In the Siebel application database, there are application tables (known as base tables), which Siebel applications use. For data to come from other corporate data sources (external databases) into Siebel application tables, the data must go through EIM tables. So the data exchanges between the Siebel database and external databases occurs in two parts:
1 Load data into EIM tables.
2 Run Siebel EIM to import the data from the EIM tables into the Siebel base tables.

NOTE: While the first part of this data-exchange process involves the intermediary tables that are called EIM tables, only the second part of the process involves the functionality of Siebel EIM.

When data is entered through the Siebel user interface, the application references properties set at the business component object type. However, when data is entered into Siebel base tables through EIM, EIM references properties set at the table object type.