Copy protection

method or effort designed to prevent the reproduction of software, films, music, and other media, usually for copyright reasons

Copying is the duplication of information or an artifact based on an instance of that information or artifact, and not using the process that originally generated it. With analog forms of information, copying is only possible to a limited degree of accuracy, which depends on the quality of the equipment used and the skill of the operator. There is some inevitable generation loss, deterioration and accumulation of "noise" (random small changes) from original to copy when copies are made. This deterioration accumulates with each generation. With digital forms of information, copying is perfect.

digital copy protection

disk sector on a disk storage unit that is permanently damaged

electronic copy protection and content protection device

thumb|Lenslok prism and audio cassette

Copy protection system in VHS and DVDs