Data Pack 1 is the first major update for PES 2017, released to enhance the gaming experience by adding new content, updating existing teams, and fixing any inaccuracies present in the base game. This data pack includes a wide range of updates such as new player faces, updated team squads to reflect real-life changes, enhanced stadium details, and more. The primary goal of Data Pack 1 is to ensure that the game feels fresh and that players have access to the most current and accurate soccer data.