Workbench is basically to integrate qlikview charts in a webpage.
QlikView Workbench is kind of add-in for visual studio.
To work with QlikView Workbench, it should be enabled in the server license. You can see these lines WORKBENCH:YES;; if your server license is workbench enabled.
After that, as usual, you can open visual studio and insert a new QvObject from the toolbox in the web page.
You can link the charts or reports of the qlikview document mounted in the access point.
Workbench is always communicates to QlikView Server to pull the objects to show it in the webpage.