Yahoo Fantasy Sports is an online platform that allows users to create and manage their own fantasy sports teams across various sports, including football, basketball, baseball, and hockey. Participants draft real-life athletes to form their teams and earn points based on the players' actual performances in games. The platform offers various features, such as live scoring, player statistics, and customizable league settings. Users can join public leagues or create private leagues with friends, making it a popular choice for both casual and competitive players looking to engage with their favorite sports in a fun and interactive way.