Nor Easter

I am watching the news and they're talking about the storm that is hitting the New England area in the U.S. They call it the Nor Easter. As they are talking about I'm gathering that it happens every year, it's just not as strong as it has been this year. Apparently I caught the ass-end of the story because I know nothing about it. Why do they call it the Nor Easter? How long does it ususally last. Does it happen every year or did I hear them wrong? Please give me answers!!!!!