One of the sports at the Tokyo 2020 Paralympics that people around the world have been googling in the early days of the Games is goalball. It's a bit like handball and is contested by athletes who are visually impaired.
According to the Tokyo 2020 website, the sport was created by injured soldiers returning from World War II and is now played in more than 100 countries.
The court is 18 meters long and 9 meters wide (59 feet by 29.5 feet) -- roughly the size of a volleyball court. Three players per team are on the court at a time, with the task of trying to roll a ball into the opponent's net while also defending their own goal, which is the width of the court.
But how do they know where the ball is? The hard-rubber ball has bells inside that can be heard when the ball moves. One of the strategies is to roll the ball so slowly that the other team can't hear it approaching. Another is to throw the ball hard and fast, forcing the other team to react quickly.
Because each player may have a different level of visual impairment, all of them wear eye shades to ensure an even playing field. Lines on the court are tactile so players can get their bearings.
This is also a spectator participation sport, but not in the traditional sense. Spectators are expected to be as quiet as possible so the competitors can hear the bells in the ball. Since no fans are being allowed at the Tokyo Games due to COVID-19 restrictions, this is not a problem this year.
Games are played in two 12-minute halves. If there is overtime, another two periods are played, each lasting three minutes. If the game is still tied after that, extra throws will determine who wins.