Your question is valid but there is a custom in most of the firms that people don't tell their salary. It may happen that people in your team is getting more salary then you because they are a bit of experience than you. At that position, you can't yell with your authority regarding this. But in some cases, if the person is close to you, they may tell their salary otherwise no one would. There is no point in knowing someone else's salary, it's not going to help you in any way. Better would be, try to work hard and get the place to earn respect as well as the appraisal.