How does ID3 editors work under the hood? [closed]

I want to try making a ID3 metatag editor as a fun project using JavaScript, and Tauri. I know there are libraries out there, but I was wondering how it acturally works under the hood. I am between the range of a beginner and a indeterminate, so it’s hard for me to comprehend a lot of the code with my limited skill and experience. I just want to know the very basics of how they work, and possibly, how I can use JS to code it; if it is not too complicated.

I tried browsing YouTube, Reddit, and Google, but I cannot seem to find an explanation of how they acturally work. Some that I found were of other languages, which I do not understand.

Thanks in advance.