The exposure triangle shows, graphically, the impact and the compensation that must be made for each of the parameters to ensure an image with the desired exposure. If you move one side towards “less light” one of the other sides must move towards “more light”.
Note that I said “desired exposure” and not “correct exposure” as “correct exposure” might mean that the image has no dark areas without detail or burnt areas and, in some cases, may even be the intention.

When reading the triangle can be seen that, for example, to increase the F (reducing the amount of light passing through the lens and improve DOF) one has to increase exposure and / or increase the ISO (increasing the grain on the picture . If the idea is to freeze the motion shortening the exposure compensation would be to decrease the F (increasing the amount of light passing through the lens and decrease DOF) and / or increase the ISO (increasing the grain in the photograph).
We can observe the variation of the impacts of any of the parameters on display can be seen on the scale of “exposure compensation” ranging typically from -2 to +2 stop’s.

By placing the camera in M mode carry out a measurement (press the photo button halfway). Then adjust the speed so the dot stays in the middle of the scale (0). Increase the ISO to double, measure, see what you have to change to replace the measurement in (0).