FLAC is a free cross-platform audio codec format created in 2001 by Josh Colson and Xiph.Org. The name of the format is an abbreviation of the English phrase Free Lossless Audio Codec. When compressing a file into the FLAC format, it is 50-60% of the original file without loss of sound quality (especially when working with voice recordings). When unpacking such a file, absolute originality is respected. Since the format is free and open, it is supported by almost any software, it is perfect for archiving files and for regular listening to digital recordings.
AMR is a sound file format with a specific focus. Created a long time ago, before the advent of MP3. some sources call the developer Ericsson. The name of the format is an abbreviation for Adaptive Multi Rate. Sound files of this format are intended for mobile devices and in GSM cellular networks. Using this format provides a small file size due to the technology of signal coding in the speech frequency range. Effectively compressing audio recordings of human speech makes this format often used in voice recorders on mobile phones, for voice recordings, and for MMS messages.