Architecture of the SAP DB Loader 
The SAP DB Loader has a client/server architecture.
· Clients: SAP DB Loader CLI (LOADERCLI), clients through Perl, Python and JAVA interfaces
· Server: Loader.
The SAP DB Loader is also remote-enabled, which means that the SAP DB Loader and database instance can be installed on different computers.
The
client of the SAP DB Loader (for example, SAP DB Loader CLI) is
remote-enabled, which means that the client and Loader can be installed on
different computers. It is important that the
media (for example
files) of the SAP DB Loader must always be on the computer that the Loader is
installed on.

In practice, the following configuration is
frequently used:
All SAP DB Loader components are on one computer, and the database instance is
on another computer.

...
1. When requested by the client (for example, SAP DB Loader CLI), the Loader is started directly, without the X server being called.
2. Communication between the Loader and the database kernel is established via the X server.
See also:
Architecture of the SAP DB Tools