IT professionals build, design, and maintain the systems that handle storing, sending, and retrieving information. Employers are looking for individuals who are able to systematically solve the tough and unusual problems that arise in the field. Expect to be asked many hypothetical questions that will assess your thought process when dealing with complex problems.
The interviewer asked me a very pointed question about one of my past experiences listed on my resume. It had been a while since I'd thought about this particular line item, so I struggled to give specific details when relating my answer. Make sure you thoroughly review your resume before going into the interview - this is where many of the behavioral-based questions will come from!