MP3 is a standard audio format developed by Moving Picture Experts Group and uses MPEG-1 and MPEG-2 standardizations. MP3 uses lossy data compression, meaning that it loses quality over time. This sound format comes with a .mp3 filename extension and is today the most common audio format on websites and multimedia players.
Windows Media Player iTunes, Mplayer VLC Media Player
HEVC MKV is a digital media format that uses HEVC codec, instead of the usual H.264, which is used on typical MKV files. HEVC MKV files are encoded at lower bitrates than H.264 MKV, making them smaller by up to 50%. However, software and hardware support for HEVC MKV files is quite limited as opposed to H.264 MKV, which ranks among the most popular media formats today.
VLC Media Player
MKV File Player