It sounds odd to me too, but I found a wiki article on it: https://en.m.wikipedia.org/wiki/Positive_anymore

I did a lot of research on digitizing old VHS tapes and ended up going with a local, professional service to have mine converted.

If you want to do it yourself, this site and its associated forum are a great starting place to learn how: https://www.digitalfaq.com/editorials/digital-video/professional-analog-workflow.htm