About working with multiple datasets
Geoprocessing is not always done with a single dataset, but can involve multiple datasets. Sometimes they are multiple sets of data that you want to process the same way, such as in a batch process. Other datasets need to be merged together, and their fields must be mapped to make this possible. Some geoprocessing tools accept multiple datasets as input. This section in the software development kit (SDK) covers additional information for performing geoprocessing tasks with multiple sets of data.
See Also:
How to list dataMapping fields
Using value tables
How to use multiple inputs
Samples: