Aperture value

The aperture value works a lot like a pupil. It decides how much light to let into the lens along with ISO and Shutter speed. When it's light outside your pupil will naturally close so that the eye can adapt to the light surroundings. When its dark the pupil becomes bigger to absorb all the light it can find. This is also the case with aperture value.

One can also decide how much information we want to put into the picture by using different values. We can focus on all the things in the picture and make everything clear or we can focus on one object and make the rest blurry.

For example if you were to take a photo of three cups and you wanted only one cup to stand out, while the rest are blurry, you set your camera to low aperture value. 

If you want all the cups to be in focus you change your settings to high aperture value. 

Inside of the camera there is an opening that looks like this: 

A large opening makes a photo with one focus and the rest blurry, while a small opening makes everything in the picture turn out clear. 

You will find these settings if you turn the wheel on your camera to ''Av'' or ''A''. Then you can turn the other wheel to choose how high or low you want your values to be.