AIFF vs Apple Lossless
If you want to get the best audio quality from your music files, you should opt for a non-lossy audio encoding format. AIFF and Apple Lossless are two non-lossy formats. They both keep the audio information intact and no data is lost no matter how many times you convert between non-lossy formats. The primary difference between the two is the use of encryption. Although there is a version of AIFF that uses compression, it is basically an uncompressed format. On the other hand, Apple lossless uses compression.
Compression does just what it says, it compresses the data with the use of algorithms in order to minimize the disk space that it occupies. The better the compression, the smaller the file size; without sacrificing any bit of audio information. Because of compression, Apple Lossless files are smaller compared to AIFF files by about half. The differences of these two are of little importance when you are using a computer which has a lot of drive space and processing power; unless you are short in both areas. But the differences become very relevant on portable music players.
When using AIFF, the large file sizes means that your player needs to read more data from the hard drive, causing it to consume more power. The effects of caching is also quite minimized with AIFF due to the large size and the limitations of the cache. Frequent hard drive access results in greater battery consumption and could quickly rundown your battery.
Because Apple Lossless files are compressed, the player needs to decompress it before it can be played back. The decompression adds extra load to the processor of the player. In most of the newer music players, this should not be a problem but for older players with weaker processors, it can result in a bit of lag before the song starts playing. This problem is not present with AIFF since no decompression is needed and the data is readily available.
AIFF is very old and a lot of other alternatives exist that are better. Apple Lossless is one alternative and it is significantly better than
Summary:
AIFF does not employ compression while Apple Lossless does
AIFF files are much larger compared to Apple Lossless files
AIFF files can drain your batter quicker compared to Apple Lossless
AIFF requires lesser processing power compared to Apple Lossless