The Multiplayer Trivia Quiz Application is a real-time multiplayer game built using Node.js, JavaScript, HTML, and CSS. It allows users to create rooms with unique room keys for identification and join existing rooms to participate in trivia quizzes. Room creators have the flexibility to customize various aspects of the quiz, including the number of questions, trivia category, and the time allotted for each question. The application updates scores in real-time, providing an engaging and interactive experience for players.