I bought all of these things in Italy. I think it amounted to a total of around 5 or 10 euros. My oh my, what our hands can hold.
Exposure - The amount of time that you are allowing the shutter to be open. The longer it is open, the brighter your picture will be. The shorter your shutter is open, the darker your picture will be.
Displayed as: 1/200 or 1/1000 or 12...etc
1/200 or 1/1000 or 12 represents how many seconds the shutter is open for.
ISO - The sensitivity to light. The higher to ISO, the more sensitive it is to light, and it will be more grainy. The lower the ISO, the less sensitive it will be to light, and it will be less grainy. If you are shooting in a dark area, a high ISO is better. Vice versa for a light area.
Displayed as: ISO 100 or ISO 1600 or ISO 1600...etc
Aperture - The size of the opening in a lens when taking a picture. When the aperture is higher, the hole will be smaller. This will make the picture darker. When the aperture is lower, he hole will be bigger. This will make the picture brighter. Also, when the depth of field in larger and the aperture is lower, there will be a blurrier background.
Displayed as: f/1.4 or f/22 or f/13...etc