Optical disc composed of a phase change material, most often AgInSbTe, an alloy of silver, indium, antimony, and tellurium. Optical discs are most commonly used for storing music (e.g. for use in a CD player), video (e.g. for use in a Blu-ray player), or data and programs for personal computers (PC). The Optical Storage Technology Association (OSTA) promotes standardized optical storage formats. Although optical discs are more durable than earlier audio-visual and data storage formats, they are susceptible to environmental and daily-use damage. Libraries and archives enact optical media preservation procedures to ensure continued usability in the computer's optical disc drive or
Optical disc authoring recorders. There are, however, stand-alone devices like personal video recorders which can also author and record discs. Use of optical disc recorders require "optical disc authoring software", sometimes called "burning applications" or "burner applications". Such software is usually sold with the recorder. Some operating systems come bundled with them. Creating an optical disc usually involves first creating an optical disc image with a full file system designed for the optical disc, and then actually burning the image to the disc. Many programs create the disc image and burn in one bundled application (Quick Copy or Copy On-the-fly), such that end-users