Change setting to make the camera sensor more or less sensitive to light. Lower ISO equals lower sensitivity. Higher equals higher. Lower ISO produces sharper images and better color. High ISO has more digital noise but is better for low-light and fast action.
Measured in fractions of seconds, shutter speed control or exposure time controls the brightness of your photos and can create dramatic effect by freezing or blurring action. Remember, faster shutter speeds need higher ISO settings for more light.