ADO.Net communication is limited to tabular set of data or responses where as WCF communication can have XML type,soap messages.

.Net Applications ------ ORM -----ADO.NET and .Net, Java , etc.......WCF ---------ADO.NET

Did they ask, WCF data services and ADO.NET data services? If that was the case then both are the same.WCF Data Services, formerly ADO.NET Data Services(Astoria), and this is a platform for Data Services. Regards Baimey

http://www.slideshare.net/umarali1981/differences-between-windows-communication-foundation-wcf-line-ofbusiness-lob-adapter-pack-and-the-biz-talk-adapter-framework

I'm not sure of the answer but what I answered was the communication in WCF happens using XML and/or over a network communication channel. And communication in ADO.NET happens over socket.?