Summarize this article in one sentence.
If you are selected through the lottery, you have only until the end of the applicable U.S. fiscal year to apply for, and obtain, your visa. For example, if you applied during the 2013 application period, referred to as DV-2015, you will be able to find out about your selection beginning May 1, 2014, and you must apply for and obtain your visa during the 2015 fiscal year, which is October 1, 2014 - September 30, 2015. When you check on your status through the Entrant Status Check link, if you are selected, you will receive online instructions on what to do next. Next steps will include being interviewed at a U.S. Embassy or Consulate. The DV program advertises that 50,000 green cards will be issued. In order to take into account the fact that many of the candidates in the lottery who were selected will probably NOT meet the requirements to obtain a green card, the DV program actually selects 125,000 people. This means that as soon as you submit your application, you will receive a Diversity Visa Rank Order number. The number is located in the Diversity Immigrant Category of the Visa Bulletin, https://travel.state.gov/content/travel/en/legal/visa-law0/visa-bulletin.html. Look for the region that you belong to. If your Rank Order number is really high, chances are the 50,000 visas will be issued before your application is processed and so you cannot immigrate. If you are already in the U.S., you may be able to apply to the U.S. Citizenship and Immigration Service to adjust your status to permanent resident. To do this, you need to be otherwise eligible to adjust your status, and you must make sure that the USCIS can complete action on your Diversity Visa case, including processing your spouse and children during the program’s time limits.

Summary:
Be aware of time limits. Follow the Entrant Status Check instructions. Apply as quickly as you can. Consider adjusting your status, if you are already in the United States.