Rafflecopter is a tool that allows you to create online random raffles. The document provides step-by-step instructions on how to set up a raffle using Rafflecopter, including adding prizes, setting entry options and dates, installing the raffle widget on a Facebook page and WordPress blog, selecting a random winner, and announcing the winner. The key steps are signing up for a Rafflecopter account, customizing the raffle details, getting embed codes to display the raffle widget, and moderating entries and selecting a winner.