What they're looking for here is for you to summarize your qualifications for the job. Most of it should already be on your resume really, you just need to expand on that a little with the "soft stuff" (character traits etc). Really...they don't want to hear about addiction to japanese animation here, just stuff that is relevant to the job
I start off by describing my education and then a few soft skill traits (analytical, big picture person etc). They're likely to ask you to elaborate on the soft skills so be prepared to give some examples of how you have shown those traits.