Cd key

A Product key (also referred to as a CD key) is a specific software-based key for a certain program or a computer game. It is used to identify that the copy of the program/game is original. Activation is sometimes done offline simply by entering the key, or with software like Windows XP online activation is required to prevent multiple people using the same key.

Computer games use product keys to verify that the game has not been illegally copied; for example, one could not play Diablo II or Starcraft online without an original/unique product key. Another example is Battlefield 2 or Battlefield 2142 will not allow you to play online when two identical product keys are online at the same time.

Product keys consist of a series of numbers and/or letters. This sequence is typically entered by the user during the installation of computer software, and is then passed to a verification function in the program. This function manipulates the key sequence according to a mathematical algorithm and attempts to match the results to a set of valid solutions.