Mastering is the last stage in the process of releasing the music out into the world. A hands-on quality control, the final polish, to ensure that it sounds the best that it can in all possible playback situations and making sure that it fits together seamlessly so the sound doesn’t vary from track to track. Mastering also deals with unwanted noise, clicks pops, device hum, artifacts, front and end fade-ins and outs, as well as preparing the music for distribution in different formats. More and more pros are embracing the high-resolution distribution and playback formats as well as devices that play uncompressed formats for better reproduction of music.