A judgment in a case for unpaid bills is a judge's decision that says you owe a certain amount of money to a certain creditor. It is a court order that says you owe money to a specific person or company.
A judgment lasts for 20 years. If at some time in the 20 years after the judgment you have wages or assets, the creditor may attach or take your wages or money to pay the debt. They could also take your assets and sell them to pay the debt. Do not ignore any paperwork from the court even if you do not have the money to pay the debt now. You do not want to have a default judgment entered against you, especially if you do not owe the money.