MKV is a container format for holding multiple audio, video, picture, and text data such as subtitle tracks. It is similar to other common containers like MP4 and AVI, although MKV is open in the specification. For video contents, MKV uses a .mkv filename extension, .mka for audios, and .mks for subtitles.
MPC-HC, KMPlayer VLC Media Player MKV File Player MPV
OGG is a free audio container format developed by Xiph.Org Foundation. Its unrestricted design offers efficient manipulation and streaming of high-quality digital multimedia. It multiplexes multiple streams for video, audio, text, and metadata. OGG has a filename extension of .ogg, although it can also come in .ogv, .oga, .ogm, .opus, and .spx.
Apple QuickTime Player Windows Media Player VLC Media Player RealPlayer