Does Mp3tag store any tag information OUTSIDE of the .mp3 file?

Does MP3Tag store any tag information OUTSIDE of the .mp3 file?

That is to say, if a tag is visible in MP3Tag on one computer, and that .mp3 file is moved via USB stick to another computer, also with MP3Tag installed, will all of the tags showing in MP3Tag on the original computer also show up in MP3Tag on the NEW computer???

Does MP3Tag have a database, or does it ONLY read tags held in the .mp3 file?

These were several questions.

Only if you say so, e.g. with an export for tag data or embedded pictures.
In general, all the data that you see in MP3tag is embedded in the files.

If you switch on the feature of the library then MP3tag maintains a database to deal with large collections.
The library (database) has no influence on the tag data, the tag data is always read first.

Yes.

Apologies - I rambled a bit!

Thanks for your answer. Very much appreciated.