M4A files are a type of audio file developed and popularised by Apple. Since 2007, music purchased through the iTunes store has been in m4a format, therefore accounting for over 15 billions files worldwide. MP4 and M4A files are often confused, and the two are quite similar, being both based on the MPEG-4 codec. However, M4A is a file comprising solely of audio, whereas MP4 may also contain video.
M4A files are superior to MP3 in terms of the scale of compression and audio quality. The M4A file uses Apple's codec and resides within the MPEG-4 container. The main benefit of M4A is that files are compressed but are lossless. This means they can be decoded back to the original quality they were at the point of compression. Another benefit of M4A files are that do not carry any Digital Rights Management (DRM) protection associated with other files meaning they are less restricted.
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WAV (WAVE) files are audio files playable via multimedia playback software such as Windows Media Player and other software available for your operating system. These files contain any sounds such as sound effects, music or spoken words. WAV files are large in size and with the advent of MP3 and MP4 WAV files are becoming less popular and less common. They were created and developed by IBM and Microsoft but unlike MP3 and MP4 the WAV file format does not use a form of lossy compression so file sizes are therefore much bigger and now less popular.
Wav files are the standard digital audio format in Windows. Using the .WAV file extension, 8- or 16-bit samples can be taken at rates of 11,025 Hz, 22,050 Hz and 44,100 Hz. The highest quality being th 16-bit at 44,100 HZ, this highest level is the sampling rate of an audio CD and uses 88KB of storage per second. All general sounds in Windows, such as when you log in, are in the .WAV format. The default content of a WAV file is uncompressed (although they can be used to store compressed formats such as MP3), pulse code modulated (PCM) digital samples derived from the analog source.
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