Uncompressed: the file and the data remain intact, it is an exact copy of the original (Master Recording). Uncompressed formats are WAV and AIFF. These are what you export from your DAW or SkyTracks®. If you duplicate a Recording to WAV format it’s an exact, uncompressed copy of the original.
Lossless: compression is slightly applied and the file size is smaller. The original data remains intact. It is like folding something, it remains intact but fits the size you need. Even though Lossless files are compressed they preserve the original just like a WAV. They just get unpacked when they’re opened.
The most common lossless format is FLAC. Apple also has their own lossless format called ALAC if you’re dealing with iTunes.
FLAC makes the file size smaller than a WAV while preserving the original data. But the file sizes still tend to be very big.
Lossy: compression is highly applied and some of the original data is shaved off. The lossy file is smaller to the original copy.
In MusicTeam®, we support WAV, AIFF, AIF and FLAC. We don't support MP3, OGG, M4A because they're lossy formats. We truly believe your audience deserve the best listening experience, which can't be achieved with lossy formats.