View Descriptors enable you to specify way a report appears when it is initially selected and added to a page. You can specify things like the report type, columns to include in the report, appearance of the report, report grouping and sorting and so on. The options available depend on the specified report type.
The current version of the Report Editor does not support adding or editing View Descriptors and as a consequence this must be done by editing the code of a report stored in the BrightWork Reporter Library.
Using an existing view descriptor as a starting point is the easiest way to get going with view descriptors. If you have created a copy of a report then the copy will have this view descriptor already in it.
All the reports supplied have a default view descriptor. It may be that this suits your purposes so you should review how the report first appears when it is added to a web part page.
To get the view descriptor from an existing report, open the report in the BrightWork Reporter library and copy the view descriptor. You can also extract the view descriptor from a displayed report - see Extract View Descriptor from a Report.