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.
M4R is a highly specialized audio file format. This format (full name - iPhone Ringtone File) was developed by Apple's IT giant specifically for the iPhone. This format creates music ringtones for the iPhone. ITunes Ringtone is the main program for opening files with the extension .m4r, and their creation is mainly using Apple iTunes. Formally, M4R files can only be created from songs and other works purchased in the iTunes music store. The size of the created ringtone in the M4R format can be a maximum length of not more than 40 seconds.