ok so after trying to read through many sites that explain the zone system, I think I have it figured out.
Tell me if I'm wrong.
The zone system is basically HDR with two exposures, one for shadows and one for highlights. Yes?
No.
Zone system is a way to expose & develop film to achieve a print with a wide range of tones. All tones, from pure black, to white, should be represented in the final print. It was devised using sheet film, which made it easy to adjust development times according to each images' unique needs.
For people shooting roll film, the Zone System is typically just an exposure guide. Light meters are calibrated to render a scene as 18% gray, which in Zone system terminology is ZONE V. Light meters were designed this way to give a good exposure most of the time -- i..e, darks are dark, lights are light, etc.
The key to understanding and using the Zone system is pre-visualization -- how is the scene going to look as a photograph. You have to learn to see things as a tonal quality. Google Zone System and an image of a bar with 11 tones comes up.
Look at it this way: everything in the world is shades of gray.
So when you are determining an exposure, you can choose to place tones in different zones by either underexposing or overexposing. If the normal meter reading, for example, is 1/125 @ f/8, and this normal reading yields 18% gray, or ZONE V as it is also known, then underexposing 1 stop shifts the tonal range by 1, so that ZONE V becomes ZONE IV, and ZONE VI becomes ZONE V.