StepScan is a library and (soon...) GUI application for running simple to moderately complex step scans of Epics motors, detectors, and general variables. Many concepts are borrowed from the Epics SScan record and from Spec, but neither of those are used by StepScan -- the scans happen in the python client application.
With Epics, nearly any Process Variable can be scanned or counted during a scan, and so a Step Scan can be a fairly complex thing. Fortunately, simple things are still easy to do. A description of some terms in the Step Scan Concepts section may be helpful.