A Delta is essentially a collection of DeltaChange items that is bound to one specific data table in a dataset.
When you create an instance of a delta using the constructor with a data table parameter, the Delta class will invoke the method DataTable.GetChanges to retrieve the list of updates made. It will then loop through all these changes and add a new delta change for each change.
Instances of the Delta class are created automatically by the Remote Data Adapters when you call to the Update method.
An important aspect of deltas is that they need to have a name; Data Abstract will automatically use the name of the data table contained in an Data Tables.LogicalName. Deltas without a name cannot be properly streamed or identified by the server.