Xvid (formerly 'XviD') is a video codec library following the MPEG-4 video coding standard, specifically MPEG-4 Part 2 Advanced Simple Profile (ASP). It uses ASP features such as b-frames, global and quarter pixel motion compensation, lumi masking, trellis quantization, and H.263, MPEG and custom quantization matrices.
an audio format from Apple that was developed to remove the limitations of AIFF and WAV formats. This is a container that can store sound encoded by various algorithms and track metadata. Its characteristic feature - the format doesn’t have limitations on file size and so this allows one to store infinitely long recordings.