MMO stands for "massively multiplayer online." It is a game genre. Thousands of players share the same world. They quest, fight, and trade together. World of Warcraft is the most famous. Final Fantasy XIV is another. The genre is about community. It is about persistence. The world continues even when you log off.

MMOs are huge. They have economies, guilds, and politics. They have raids that take hours. They have player-versus-player battles. They have role-playing servers. They are not just games. They are places. People make friends. People fall in love. People spend years in the same world.

Related terms

• MMORPG: massively multiplayer online role-playing game.
• Guild: a group of players.
• Raid: a large group challenge.
• Server: a specific instance of the world.

MMOs are a commitment. They require time. They require social energy. They can be rewarding. They can be addictive. The best ones build communities that last for decades. The worst ones fade away. The genre is not as dominant as it once was. But it still has millions of players. It is a world within a world.