If you need any help (googled or otherwise) to answer that question then you're clearly not qualified for the position in question and should probably stop wasting their time and yours (and, well, ours). Not to mention you need help with your reading comprehension since "fixed width" is clearly in reference to "fixed width flat files" (not that a googled answer on that is really going to get you through the interview process either).

(Yes, I'm being slightly cruel and curmudgeonly; it's virtual Monday. BMSMA.)