Shutter speed is the length of time camera shutter is open, exposing light onto the camera sensor. A longer shutter will create motion blur and a faster shutter speed will create a still clear image. a fast shutter speed will let less light (good for thing outside or fast moving) in while a slower shutter will let more light (good for taking photos at night)
Aperture is the opening in the lens which light passes to enter the camera. A way to think about it is how your eyes work. As you move between bright and dark places, the iris in your eyes either expands or shrinks, controlling the size of your pupil. A wide aperture will create a blurred background while focusing on the foreground while a small/narrow aperture will focus on the fore and background.
ISO is a camera setting that will brighten or darken a photo. A higher ISO will create a brighter image while a lower ISO will create a darker image. But as you increase the ISO the image will become grainy also known as noise. Adjusting the ISO is best recommended to use when shutter speed and aperture are unable to be adjusted.
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