Aperture

Talking about camera functions can be difficult to understand, so instead of trying to explain aperture using the functions of a camera I'll use the human eye , most cameras being produced today is designed like the human eye anyways. the human eye contains a pupil the pupil either constricts or expands depending on the amount of light that it's processing. When the doctor shines a light into your eye the pupil will constrict. if you're on a date in a low lit room your pupils will expand. The amount of light that enters the camera depends on the size of the
                                                                                   opening. You use the AV or A function on a camera. AV stands for aperture value or just aperture. While using this you can focus on a main focus point and blur the background.