Weighing is how we connect for the judge the main ideas from each side. We are directly comparing your impacts against your opponent's.
To avoid conceding an argument, get used to using the phrase "even if". This is useful when you want to hold your impact higher than your opponent's without sound like you're conceding that your opponent has a good point. Even if what my opponent says is true...
Remember that nothing you say is going to be 100% obviously correct while your opponent is 100% obviously incorrect. Weighing recognizes and accounts for that reality by saying that even if my opponent has a valid point, mine is more valid.