It is a board of engineers (which will become your peers) to ask about specific categories of skills. You don't need to know everything but it helps to be well rounded.

I received an email to attend a hiring event here in Florida where multiple managers, recruiters and positions would be available. I arrived early and dressed in business attire. There were over 200+ potential employees with notebooks prepared for an "elevator speech". I located the position I wanted and spoke with a panel of managers in private. The Interview began with personality-based questions attempting to break the ice and build some familiarity with each other. I brought several resumes copies and individually handed it to each supervisor. We went over my skills & experience and dove into more technical based questions from there. I highly encourage you be prepared and familiar with your resume. I did not know the answer to all the technical questions they asked and wrote the question down with the name of the person that asked it. I later in the week was able to get a hold of each one and gave them their response as well as an update on my latest achievement that highly encouraged their decision in sending me an offer.

Applied through school career fair. One on-campus interview. Interviewers were professional and laid back. Mostly behavioral questions and some technical questions. Overall a great experience, and a great first impression.