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.
AU is an audio file format created in Audacity. This is a free cross-platform program designed to edit audio files. AU format (Audio Units) was developed by Sun Microsystems. This format greatly simplifies the task of reliable storage of audio files. An AU file consists of 3 parts: a header (max. 24 bytes), a description block of various sizes, and audio data. The file format is used on computers running the Sun or Unix operating system. However, it opens with other audio players. The AU format uses the logarithmic encoding method, previously very popular on computers running the Sun SPARCstation operating system. Previous sound file formats, in order to reduce the size, used the logarithmic scale of recording samples. Among the representatives of such formats, the Sun AU group of formats, which are still in action, gained great fame. Problems with opening the AU file usually manifest themselves when there are no corresponding applications that would be installed on the PC. Applications that use .AU files are Apple QuickTime Player, Microsoft Windows Media Player, Real Player, Winamp, and other widely used audio players. And this is the vast majority of professional audio editors.