M4A is a filename extension for AAC container format and is developed by Apple Inc. M4A music is bought on the iTunes Store and does not come with DRM protection. In terms of quality, M4A is better than MP3 because it is lossless but still compressed. This means that it occupies less storage space and doesn’t lose quality over time.
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AVI (Audio Video Interleave) is a digital multimedia container format developed by Microsoft in 1992 for its Video for Windows project. This file format saves both video and audio data in its container that supports synchronous audio-with-video playback. And like DVD format, AVI allows multiple audio and video streaming as well.
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