I am pretty new to the SCADA world. I wanted to know what are the advantages of using a paid proprietary SCADA software such as WinCC, Wonderware, cimplicity over free software such as OpenSCADA, OpenAPI, IndigoSCADA and so on. I have read, there are more layers of security in the paid one. What does that mean? What are the other main differences between the paid and free ones out there in the market?