ALAC is the format of a small specialized program called an audio codec. Its main task is to compress a file with digital music without losing its quality. The name of the format created by Apple's IT giant is Apple's abbreviation Lossless Audio Codec. This format may also be called ALE (from Apple Lossless Encoder). Files in this format can play devices even with limited computing resources - such as an iPod. When compressing a file in this format, it is approximately 40-60% of the original file. Now almost every multimedia player based on the libavcodec library is able to play ALAC format files.
ASF is a media file format developed by Microsoft. This format is preferred for Windows Media. This player can play not only video or audio files, but also mixed recordings that are compressed using certain codecs and saved in an ASF file. Files of this format also additionally store metadata (including title, author, copyright information). The full original name of the format is Advanced Systems Format. The main goal of Microsoft in developing this format was to provide streaming media playback.