io games are simple yet addictive online multiplayer games that can be played directly in a web browser. The “.io” comes from the domain name originally used for the British Indian Ocean Territory, but it became popular for games because “IO” also suggests input and output. These games usually feature easy-to-learn mechanics, minimal graphics, and fast-paced competition, making them accessible for players of all ages. Popular examples include Agar.io, where you control a cell that grows by eating smaller cells; Slither.io, a modern twist on the snake game; and Krunker.io, a pixel-style first-person shooter. Most io games allow you to compete against players from around the world in real time, with leaderboards that encourage competition. Their quick matches, simple design, and social gameplay have made .io games one of the most popular trends in online gaming.