ISO. What is it?

ISO 3200 setting.

ISO 200 setting.

1.  The advantages of shooting in high ISO in dark lighting, is to capture the image better. Especially when its involving a faster object being shot like basketball.

2. The author basically suggested to stay in low ISO, well if theres plenty of light.

3. The author said pretty much the opposite of low ISO, using it when there isn't enough light and when trying the capture an image more faster,