MPGA is one variation of the common digital audio file format (or MPEG Audio). The full name of this format is MPEG-1 Layer 3 Audio File. MPGA format is considered standard for Windows and is supported by all players of this operating system. Any multimedia software that supports MP3 format can work with MPGA audio files. MPGA files are small in size and have significant compression, and file compression is performed without loss of quality and preserving the original sound. The massive use of MPGA is related to the Android mobile OS.
OGA is a format of free container audio files, a kind of audio container. The developer is Xiph.Org. The full original name is Ogg Vorbis Audio File. This audio container runs on Ogg Vorbis, a widely used audio encoding and streaming technology. The container stores audio data with compression using Vorbis compression. OGA audio files can also use the .OGG extension because they are a standard Ogg container. Any Ogg-enabled media player must play OGA audio files.