If you are in the USA and WIN the DV Program

 There are so many people who are in the United States and participate in the Diversity Visa Program. When they win, their processes are a little bit different from people who are outside the United States.

If you're already in the USA, you will not go to the US Embassy for the visa interview. You will need to do the so-called ADJUSTMENT OF STATUS by filling I-485 form. Why is that so?