"Big Dad"

This is my very handy husband in his workshop. He is making a small thing for the boat and is busy working out diameters, screw threads and tolerances.
I have heard a lot about lathes, milling machines and different screw threads over the years . I have tried to understand but I must confess to not being very good at all that stuff.
He now has to listen to me talking about isos , apertures and f stops !