aperture.
The aperture controls the quantity of light which enters the lens , you can have a lot of light or you can have very little light entering the lens but it is always open . It looks like this inside-
shutter speed.
The shutter speed controls the duration of light which goes into the camera once you are taking the photo. It is open or closed at all times.
iso.
ISO controls sensitivity in cameras. It is like when you walk into a dark room and your eyes need a few minutes to adjust or the other way around , when you walk outside and it is really sunny and your eyes adjust so you can have a clear image.
a few of my examples...
over exposed.
It is over exposed which means that the point on the exposure line is on -3 to 0. It lets too much light enter the camera so the photograph comes out white and its too bright to see anything.
under exposed.
It is under exposed which means that the point on the exposure line is on +3 to 0. It does not let much light enter the camera so the photograph comes out too grey and its too dark to see anything in the picture.
perfect exposure.
i call this ''the painter''
I really like this picture because it has the perfect expousure and you can see the contrast in colour between the blue and the black wall. It has "perfect exposure" because the point on the exposure line is on zero.