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.
WMA is an abbreviation of Windows Media Audio. The WMA format is designed by Microsoft as an alternative to MP3. The WMA format is characterized by good compression ability and competes with the audio format from Apple AAC. This file format is supported by many portable audio players like the most widespread and common MP3.