The title requires a little understanding of Revit. I note this because the as far as I can tell the term is unique to Revit. ArchiCAD uses term Components & GDL. Vectorworks calls them Plug-In-Object (PIO). I can keep dissecting the term but for now, I wanted to focus on the software I utilize for my production. In the days of CAD we had Blocks. These were small drawings that could repeat the graphical part of a drawing over and over while holding different attributes of information.