This is what I do:
(Which is by no means 'the techincal' way)
I play the movie in the media player, pause it at what I want to copy, then I push the [Print Scrn] button on the keyboard. It automatically copys your screen on your clipboard. I then go to paintbrush or what have you and click paste. I then erase all the junk I dont need.
This is how I get most of my Björk avatars! 😎
Imagine, if you will, the means by which car bonnets or garage doors are made, for example. A male and female version of the shape/pattern are manufactured from tool steel, which is then hardened to increase wear resistance. These are then fitted into power presses, which come in a variety of sizes. A sheet of material is then placed between these mating "dies" and the machine bumps up and down to produce the desired shapes.
Thats the really really short version that I usually use for non-engineer. 😄
I always describe big object to impress people, press tools are also used to produce tiny little things like electrical clips and picture frame hooks.
I've worked on both ends of the spectrum too, from an electrical clip that was about 15mm long and 3mm wide up to a pierce and blank tool which produced the outer casing of a bomb! I had to use a 2 tonne gantry to get that baby apart.