What is an OGG file?
OGG stands for Ogg Vorbis Audio File and is a widely used format owned by the Xiph.Org Foundation. It follows the Vorbis audio compression that can drastically reduce the size of your files. You can open OGG files on every leading player like VLC, Winamp, Groove, and Windows Media Player.
What is an M4A file?
M4A is a popular audio format that follows either the Advanced Audio Coding (AAC) codec or the Apple Lossless Audio Codec (ALAC). The files downloaded from the iTunes Store are stored in the M4A format and can be opened via iTunes, VLC, Groove Player, and so on.