NFL spreads are a popular betting mechanism that levels the playing field between two teams by assigning a point differential. The favored team must win by more than the spread for a bet on them to pay off, while the underdog can either win outright or lose by fewer points than the spread. This system adds excitement to games, as fans not only cheer for their team to win but also for the margin of victory. Understanding spreads is crucial for bettors, as they influence betting strategies and potential payouts throughout the NFL season.