That's all well and good, but can someone explain what this means in laymans terms?

I have searched the boards and found emission testing failure is common in NJ especially with Volvos, and it is sometimes hard to clear the codes. I am getting worried, because though we got a great deal on the car, we NEED a good inspection sticker. The car runs great, no problems, save for the emissions failure today.

If someone else who has been through and failed the emission testing, particularly in NJ, can pleae give me some advice, I would greatly appreciate it, before we go around and round with the DMV. Thanks.