If you want to take your photography to the next level you’ll need to learn
what some of your camera’s manual settings mean, and how to make them
work for you. ISO is a good place to start.

ISO stands for International Standardization Organization and their film
speed ratings are used to indicate the amount of light necessary for a proper
photo exposure. A film, or digital media, rated at ISO 200 requires half as much
light as digital media rated at 100.

This means you can take a photo in less light. The higher the ISO speed  
the ‘’faster’’ the digital media is. 400 is faster, or requires less light than 200.
200 is faster than 100 and so on. ISO speeds generally range from 100 to 1600.

More on ISO speeds in the next post