nprinting on-demand is part of nprinting server
it enable users to call for reports and task using qlikview extensions or any other web page using the nprinting web service api
in smb qlikview clients you can install an nprinting server without the on demand capabilities
it call nprinting server distribution only , and later the client can upgrade to the full server
On-demand is a component that comes with Nprinting. If you want to use On-demand, while installing you can only install On-demand components from the installation setup on the dev server where the Nprint client is installed.
You can install Nprint server as a standalone. Hope the below link might give you more information.