What “uncompressed” actually means for audio
WAV stores audio data essentially as-is, with no compression algorithm discarding or approximating any of it — every bit of the recorded or source audio is preserved exactly, which is why WAV files are significantly larger than MP3 or AAC files of the same length. This isn't inefficiency for its own sake; it's a deliberate trade of file size for absolute fidelity, with nothing about the sound altered or removed in the process of storing it.
For comparison, a few minutes of CD-quality WAV audio typically runs 30-50MB, versus a few megabytes for the same length at a reasonable MP3 bitrate — that size difference is the direct, visible cost of losing zero information versus a compression algorithm's calculated guesses about what you won't notice missing.
Why editors and professionals specifically want WAV
Audio editing software works best with uncompressed source material because compression artifacts can compound and become more audible through multiple rounds of processing — starting from a WAV file means every edit, effect, and adjustment is working with the full original data rather than something already partially degraded. This is the core reason WAV remains the standard intermediate format in professional audio workflows even though the final distributed product is often compressed.
If you're planning to edit audio significantly — layering, effects, precise cuts, mastering — starting from or converting to WAV before that work begins avoids compounding compression artifacts that would otherwise accumulate through the editing process.
When WAV is overkill
For casual listening, sharing, or streaming — situations where the destination and playback context don't demand pristine fidelity — WAV's large file size is mostly unnecessary weight, and a well-encoded MP3 or AAC file will sound essentially identical to most listeners while being a fraction of the size. WAV earns its size cost specifically in editing, archival, and audio-quality-critical contexts, not in everyday listening or casual sharing.
Converting to WAV from a lossy source has a real limit
Converting an MP3 or AAC file to WAV doesn't recover any quality that was already discarded during the original lossy compression — the resulting WAV file will be uncompressed, but its actual audio content is capped by whatever detail survived the earlier compression. WAV genuinely preserves quality only when it's the format you're working with from an already-lossless or original source; converting up to WAV from a lossy file just makes an already-limited file larger without improving it.