Processors in ServiceNow are an as yet relatively undocumented feature that is used in the system to provide different formats for using the data in tables.
Scripted Web Services give more control, but they only provide a single SOAP method. Processors let you hook into the backend of the ServiceNow platform, giving you direct access to the information sent over an HTTP session. Scripts can pick up parameters and "POSTed" data, letting you transfer information in any format you need.
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