While ISO has been typically known as being synonymous with “film speed,” or a film’s degree of sensitivity to light, the same principle can also be applied to digital cameras. In the digital world, ISO refers not to the sensitivity of film, but rather the sensitivity of the camera’s mechanical sensors.
Typical ISO ratings are 100, 200, 400, 800, 1600, and 3200. You can see that each rating is twice as fast as the one before it. The lower the ISO, the less sensitive it is to light, therefore you will need a lot more light for your photo to process effectively. On the other side of the spectrum, faster ISO speeds require less light for exposure.
Slow ISO speeds [100-200] work well in the outdoors on bright sunny days, or indoors where there are bright light sources available.
Medium ISO speeds  are generally applied to more “neutral” lighting, covering most indoor settings and somewhat overcast days outdoors.
Fast ISO speeds [800 and above] are utilized for indoor scenes with very dim lighting, or at night.
One thing to take into consideration is that the quality of your photo is also affected by ISO. Since a slower ISO takes time to process, it is able to capture finer details within a photo, while a faster ISO will typically will render the image slightly grainier.
On digital cameras like the Samsung SMART CAMERA, you can manually adjust your ISO by setting your camera to Program [P] mode and clicking the Function [Fn] button. From here, you are able to adjust your ISO speed accordingly.