If you've been on Twitter at all over the past week or so, you've probably seen your fair share of Tweets about Wordle. But what is Wordle, what do people mean when they share green and yellow boxes, and how can you play? At its simplest, Wordle is a game that gives players six chances to guess a different five letter word every day. Head over to NPR to learn more about the game, some strategies and the social media craze behind it.