Zener Diode

In this programmer schematic, it uses a zener diode to drop the voltage down from 12v to 5. In an effort to better understand how things work I have to ask how this works. Pin 14 is supplied the 12v directly after a 220 resistor but a 5.1 zener is connected as well then to ground. How does this drop down the 12 volts?


**broken link removed**

hi gator.

Look at this link.
Google Image Result for https://www.antonine-education.co.uk/Physics_A2/Options/Module_9/Topic_4/graph_5.gif

Thank you Eric, that makes more sense. I trust the schematic but I don't want to fry parts. And of course better understand why things work.