What is the difference between my MP3's post iTunes processing

Question

I have a huge old MP3 collection which I recently copied onto my mac.

I then opened iTunes and it quickly did a scan and added the files.

I then removed all the files from the iTunes library and added them again.

It then took about 30 minutes to 'process' the files and this music dir is now twice as big. It seems it placed all the files into its own media folder.

What is the difference between these files in its media folder and my original files?

Answer 1

There is no difference between the files in iTunes's media folder and your originals.

iTunes can either use original files in whatever directory you want or it can put and organise them in its own folder.

the choice of which to do is in iTunes->Preferences->Advanced the option is "Keep iTunes Media folder organised". If chosen then files are copied into iTunes Media