20Q is a popular guessing game that challenges players to think of an object while the game attempts to identify it by asking a series of yes-or-no questions. The game is based on artificial intelligence and uses a database of knowledge to narrow down possibilities based on the player's answers. Originally created in the 1980s, 20Q has evolved from a simple handheld toy to an online game and mobile app. It can guess a wide range of objects, from animals to everyday items, making it an entertaining way to test one's knowledge and creativity.