Open Masterdata stands for the on-demand data supply of the trade with product master data. This replaces outdated master data processes based on Datanorm. Every craftsman gets exactly those items out of hundreds of thousands or even millions that he really needs at that moment (on demand). The same applies to the data content. For example, if you don't need logistical data, you don't have to store it on your computer. The processes run in the background via WebServices, which means that every craftsman is perfectly provided for in every process step of his business, but does not accumulate any data waste.
You can find further information here.