The operator control window that pops-up after selecting an operator contains GUI elements for configuring the parameters of your operator. In addition, it provides you with buttons to run the operator.
The menubar of the control window has the following items:
"File", where you can save and load the current parameter settings, and where you can close the window
"Actions", where you can run the operator and do a validation of the parameters, i.e. check if all parameters are properly configured and the operator is ready to run
"View", where you can switch the view between displaying all parameters ("advanced") or just the basic parameters ("standard") of your operator
"Help", where you find operator-specific online help
At the bottom of the window a statusbar is located that displays to you the current status of the control window, e.g. if the operator is running.