Grand Theft Auto IV, commonly known as GTA 4, is an open-world action-adventure video game developed by Rockstar North and published by Rockstar Games. It was released in 2008 for PlayStation 3, Xbox 360, and Microsoft Windows.

The game is set in a fictionalized version of New York City called Liberty City, and the player takes on the role of Niko Bellic, an Eastern European war veteran who comes to the city in search of a better life. The player can freely roam around the city, interact with non-playable characters, and complete missions to progress the game’s story.

GTA 4 was praised for its storytelling, characters, and open-world gameplay. It also introduced new features to the series, such as a cover system and the ability to use mobile phones. However, the game was criticized for its sometimes clunky controls and for being more serious in tone compared to previous entries in the series.

Overall, GTA 4 is considered a highly influential and important game in the history of the open-world genre, and has sold over 25 million copies worldwide.