WHY RENAMING A FILE ISN’T THE SAME AS CONVERTING IT

Summary from the TLDR Web Dev newsletter

When you convert a file, such as an M4A to MP3, it involves several steps like decoding, re-encoding, and copying metadata. On the other hand, simply renaming a file doesn't change its internal data or format - it remains encoded in the original format. Changing a file's extension by renaming it may result in losing metadata.