This question is applied mostly in interviews for other forms of scholarship than social.
You need to realize one thing. There will be many applicants like you. Many people want to get a scholarship, even some who do not need it. What’s more, the background and the profile of every candidate is pretty similar. Just think about it–you all graduated from the high school, none of you have any working experience, you are all trying to make a career in the same field of education/sport.
It is not an easy task for the committee to decide whom to grant a scholarship. What would you do standing in their shoes? The best thing they can do is to ask what makes you special, or, said in other words, why you should get a scholarship and not someone else.
Focus on something that distinguishes you from the crowd
To say that you are an excellent student or a sport talent (depending on the form of scholarship you try to get) would not help you. All people who apply share that characteristic. You need to bet on other qualities. Either you can write down all your achievements, and try to present yourself as the greatest talent of all (what I would not recommend, but it can work in some instances), or you can talk about other qualities you have, or alternatively about something you can do for the educational institution. Or, you can bet on humility, saying that nothing makes you special, that you are just another kid from the block :). Let me show you a sample answer for each scenario.
I know that you meet many great athletes and that, similarly to me, they all have the desire to become professional and represent the school, as well as our country on the scene of sports. However, not all of us can make it, and will make it. While I hope to be the one who can make it, I do not want to underestimate anything, and have also a plan B. I plan to study really hard and do my best to obtain a coach license. If I get injured, or for any other reason can not progress in my sporting career, I would love to stay at the school and teach or train. So, if fact, my scholarship would be an investment into your own institution, doesn’t matter if I become professional athlete at the end, or not.
Please, see the list of my achievements. As you can see, I always strive to be the best and I am winning a lot of competitions. Also, as you can see on these pictures, I always run in a school jersey and in my speeches for local media appraise the institution and the coaches. I believe that I can help to spread a good name of your school, if I get a chance to study here.