M4R or iPhone Ringtone is the format of ringtones for mobile devices from Apple. This is the same format as M4A but with it has several limitations. The duration of the audio stream should not exceed 40 seconds. In case the duration is longer, iTunes does not install the ringtone on the mobile device.
Apple Lossless also known as Apple Lossless Encoder is an open audio codec for lossless compression of digital music developed by Apple in 2004. Audio data is stored in an MP4 container with m4a extension. This codec is similar to other lossless codecs such as FLAC. Every year this format becomes more popular as it is used in iTunes and in all media devices from Apple.