The primary goal for most methods of compressing video is to produce video that most closely approximates the fidelity of the original source, while simultaneously delivering the smallest file-size possible. A variety of technologies soon emerged to do so. Shortly after the compact disc became widely available as a digital-format replacement for analog audio, it became feasible to also store and use video in digital form. The compression may employ lossy data compression, so that quality-measurement issues become important. Most codecs are typically implementations of video coding formats. Α video codec is software or a device that provides encoding and decoding for digital video, and which may or may not include the use of video compression and/or decompression.