What made you want to look up corpus uteri? Please tell us where you read or heard it (including the quote, if possible).
Confession of judgment is a legal term that refers to a type of contract (or a clause with such a provision) in which a party agrees to let the other party enter a judgment against him or her.
This is a parallel question to the previous question (what is the difference between a hearing and a trial), because, generally speaking, an order is what follows a hearing, whereas a judgment is what follows a trial. Normally, a judgment is the final, decisive act that resolves a dispute in court.