I need a cutting tool geometry explanation

Hey all, Ive been in this industry for over 10 years and worked in multiple shops. My old boss didn’t have a very good explanation of this question.

Can someone explain what the term “free-cutting” means, specifically when it comes to cutting tools? (i already understand what free-cutting steel is, yes.)

It is typically found in hi-feed style cutters and I assume it is the fact that the lead angle is negative. Or is it the rake angle? Or both?

Thanks in advance!