Honestly? It’s mostly bullshit, you won’t be able to notice much of a difference at all unless you’re using very high-end headphones plus an amplifier at the very minimum. The reality is most (if not all) consumer grade audio devices can’t reproduce the fine details in lossless files without some sort of audiophile setup and even then they’re so discrete you usually need a trained ear to notice them, so basically most people are paying for a placebo while they’d be better served with lossy formats like good old mp3.