Why does node's Toolkit for i, use a database connection to execute CL commands?

I developed the node sample app found in the following document from IBM developerWorks:
https://www.ibm.com/developerworks/ibmi/library/i-native-js-app-ibmi-with-nodejs/

The sample app executes a CL command using node's Toolkit for i. Toolkit for i is a collection of APIs for interfacing with XMLSERVICE.

Why does it look like Toolkit for i is establishing a database connection in order to execute a CL command? Here is the relevant code:

var conn = new xt.iConn(DBname);
conn.add(xt.iSh("system -i " + cl));
conn.run(cb);

The variable "cl" contains the CL command. It looks like the CL command is being executed through a database connection. Why would a database connection be needed if Toolkit for i interfaces with XMLSERVICE to execute the CL command?

Also, if I wanted to call an RPG or COBOL program using Toolkit for i, would this also require a database connection? Would the RPG or COBOL programs have to be stored procedures?

Thanks,

Kelly Cookson
IT Project Leader
Dot Foods, Inc.
1.217.773.4486 ext. 12676
kcookson@xxxxxxxxxxxx<mailto:kcookson@xxxxxxxxxxxx>