Cellar Live offers digital downloads in WAV, a hi-resolution uncompressed audio format. WAV files require considerably more disk space (about 10MB per minute) compared to MP3 (60KB to 2.4MB per minute, depending on resolution).
WAV files have many benefits, which include: ability to provide tagged files (track info, cover art), increased dynamic range, and increased frequency response. Insofar as audio is concerned, uncompressed audio formats allow the recording to retain its nuances, providing a much more musical listening experience.
Albums' tracks will be inside a .zip file, which simplifies the download process.
AIFF stands for Audio Interchange File Format, and is an uncompressed PCM file format standard used for storing audio for personal computers and other electronic devices. AIFF was developed by Apple in the late 80's, and is still used heavily today.
Here are the instructions to convert files in iTunes.