What the heck is ISO?

Are you confused about the ISO button on your camera?

ISO simply stands for International Standards Organization... yes, even on your camera, that's what it means. So basically it is referring to the fact that whatever it does - it does it so that everyone all around the world will do it the same way.
In the days of film cameras, ISO (also called ASA and DIN back then - which meant American Standards Association and DIN was German for the same thing in Germany) referred to the speed of your film. Film Speed allowed you to get better results in differnt lighting conditions. It controlled how sensitive the film was to light.
In our now digital world, it does very much the same job, just not the same exact way. So what DOES it do, you ask? It allows your camera to adapt to bright sun and dark of night so that it can still come up with an evenly lit exposure.
ISO numbers can range anywhere from 25 (usually named ISO LOW #1) to as high as 25,000 (referred to HIGH #2 and only found the most expensive cameras).
How to use it:
Photography is all about opposites; the lower numbers are for use with more light - bright sunny days on snow or frozen lakes are great for the lowest of your ISO numbers, and dark places will require the higher numbers.
It seems simple enough but there is a catch. The higher ISO numbers will have some quality loss in the form of pixels. Some cameras handle this better than others, but the trick is to use the lowest ISO number you can get away with and still have a decent exposure.
If you have never bothered to use it before, I suggest you play with it and find out how it can help your images. Just remember that you will have to take it off of AUTO to be able to adjust it. PROGRAM should allow you to change your ISO among other things. Happy Shooting!