Answer
Each ArcWeb Services data source name contains important information about the data source. Data source names always use the following format:
ArcWeb:[data provider].[type of data].[geographic region]
For example, ArcWeb:TA.Streets.NA is a street data source provided by Tele Atlas for the North American region.
If it is a custom data source, 'ArcWeb' is replaced by the user name of the person who created that data source.