The Secure Data Connector (SDC) is a mechanism whose aim is to allow Google Apps services to access enterprise data that lies behind a firewall, in a controlled way. "Controlled" here means that only users duly authorized to access this data will be able to benefit from the SDC. The SDC is an application that runs on a server in the company IS.
There are three Google Apps services that can take advantage of the SDC. We will briefly indicate for each of them how an invocation of the SDC is performed:
makeRequestAPI to access the SDC