Shutter Speed
Shutter Speed is how long the shutter stays open, meaning it lets a certain amount of light to come in and it controls the timing of how much light can enter during that time too. This can affect the picture, in two ways. It can either be a fast shutter speed, leading to a clean, clear image. Having a slow shutter speed is going to cause an image that is blurry if movement is in it, or if there is a tripod being used, it can help still the photo.
Aperture
Aperture is a measure of how much light is let through the lens and into the picture. The higher the aperture, the less light that is introduced to your photo. The aperture affects the amount of light that is let into a photo because, it can close and open up, physically restricting light to come in.
White Balance
White Balance is telling your camera how to verify the true white in your image for you. There are different settings on the camera for different locations/lighting situations with an image to adjust to relate to the exact lighting and to ientify its ture white.
ISO
ISO stands for International Standards Organization, it determines how sensitive the cameras sensor is to light. For short description, it is also known as sensitivity to light.