You are asked to provide feedback on each others' presentations, through an automated website. This is an assignment: you are expected to understand what your fellow classmates are presenting, and you are expected to assess how well they complete the assignment. You should be able to say at least one positive observation, and include at least one critical comment. Failure to provide appropriate feedback may result in a loss of points for you. You do not rate yourself. You do not rate your teammates.
Every student who presents will receive feedback. Your feedback to others will be given to them, in an anonymous way. They will know what you say, but they will not know who said it.
This automated feedback is not directly used in determining grades. It is possible to rank students according to this feedback, but this has a number of implications, such as students evaluating their friends numerically higher than they deserve, or students evaluating everyone else lower than they deserve to make themselves look better in comparison. The feedback is included for your information. However, know that students' ratings of each other are very consistent with the professor's ratings. The professor's ratings are used to determine your grade.
The goals of the feedback system are
Think of the feedback system as an exercise for you, not a grade for others. Honesty is important, as is impartiality. Your ability to accurately review others' work is being tested. If your review about someone's work stands out from the class, this could be good or bad, according to your justification. For example, you could lose points if you rate someone's work highly and say that it is flawless, when the rest of the class rates it poorly and lists several flaws. On the other hand, if you are the only one to rate another person's work highly or poorly, and you point out something relevant that no one else thought about, you could get extra points.