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, that have not sound) from original to copy when copies are made. This deterioration accumulates with each generation. With digital forms of information, copying is perfect. Copy and paste is frequently used by a computer user when they select and copy an area of text or content.
During the 19th century, a host of competing technologies were introduced to meet office copying needs. The technologies that were most commonly used in 1895 are identified in an 1895 description of the New York Business College's course program: "All important letters or documents are copied in a letter-book or carbon copies [are] made, and instruction is also given in the use of the mimeograph and other labor-saving office devices.
The same principle is applied digitally, in devices such as in hard disks, but in a different form. The magnetised data on the disk consists of 1s and 0s. Unlike DNA, it only has two types of information, rather than four types, however, it still has a polar concept of transfer. In this case, the read-write head acts as an intermediary. A data section reading "1", can only trigger one type of response, and "0" for the other. These responses from reading are converted into an electrical form that gets carried through the circuits. Although this can be later converted and processed for other ways of using the data, which can be modified, if a file was being copied from one hard disk to another, the principle ensures that the data is transferred with high fidelity, because only each type of signal can only trigger one type of data write, in this case, a 1 or a 0. This excludes exceptions where the data was written incorrectly or the existing data has been corrupted while on the disk such that no distinction can be made, but usually the hard disk returns the area as unreadable. The other concept that using digital copying is website copy, digital copying has more interpretation than just the basic concept of disk read and write itself. Digital Copy is a sample of interpretation of digital copying.