If you set up a client application exactly as described in Using a Data Library, it will work as a 2-tier application. Note that to make it 3-tier, only one additional step is necessary: setting the DataLibraryUrl property. For more information, see 3-Tier Application.

In a 2-tier application deployment configuration, a client application and the data library reside on the same machine, and there are no other computers involved except possibly a database server.

C1DataSet components belonging to the client application interact with the data library. They request data from the data library on Fill and send modified data to the data library on Update. Responding to these requests, the data library sends data requests to the database server, which can reside on the same or on different computer, according to the ConnectionString specified in the schema.

The client application fires business logic events in the data library. For example, when the end user modifies a field value in a grid, the C1DataSet component (to which the grid is bound with its DataSource/DataMember properties) calls the data library, and the BeforeFieldChange event is fired, handled by business logic code inside the data library.