Shutter speed is the time at which a shutter is open at any given time. When you want a slow shutter speed you will have it for 2 reasons- 1 reason Its dark and you need more light in the camera or 2. You want some blur in the picture.
Aperture is a space through which light passes in an optical and the varible opening by which light enter the camera.If you want a shallow depth of field (with something focused and the background blurred you would use f/1.4). If you want an image with everything in focus you would use a smaller depth of field just like f/22.
When you change your ISO setting, your adjusting your camera's sensitivity to light. ISO settings can be anywhere from 24(or lower)-6400(or higher).If you have a low setting it makes your camera less sensitive and a high setting makes your camera more sensitive. Higher ISO generally makes the picture grainy so you'll generally use the lowest ISO settings.
The white balance is the color on the camera.You might have noticed when examining shots after taking them that at times images can come out with an orange, blue, yellow etc look to them – despite the fact that to the naked eye the scene looked quite normal. The reason for this is that images different sources of light have a different ‘color’ (or temperature) to them. Fluorescent lighting adds a bluish cast to photos whereas tungsten (incandescent/bulbs) lights add a yellowish tinge to photos.
exposure : exposure triangle