What is an "Age of Empires 3" product key?

An "Age of Empire III" product key is a unique alphanumeric number usually located on the back of the CD case. The product key is required to install the game and unlocks special game features, such as updates and online gaming.

The product key is also required by the publisher to authenticate the copy of the game. The "Age of Empire III" is a real-time strategy war video game developed by Ensemble Studios and published by Microsoft Game Studios. It was first released in 2005, and the developer subsequently released two sequels thereafter. The game is available for play on several platforms, such as Microsoft Windows, Windows Mobile, Mac OS X and Nokia N-Gage handheld game system.