WMA is a widespread licensed audio stream compression format. Created in 1999 by Signal Processing Group, a member of the IT giant Microsoft. Initially, this company created WMA as a competitor to the popular MP3 format. The name WMA is an abbreviation for Windows Media Audio. Among the advantages of this format is the support of almost all Windows systems and devices, as well as the similarity in characteristics and quality with MP3 files. It is believed that a compressed WMA audio file with a bit rate of 160 kbit / s is fully consistent with the quality of an MP3 file with a bit rate of 256 kbit / s. Today, even Apple devices support the WMA format.
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.