Exposure parameters in nikon d40?

I have a question for you, since I control the main exposure parameters in manual mode (stutter speed, aperture and ISO) what is the exact use of the exposure compensation? (EV)
In other words when must I use the EV and when use (stutter speed, aperture and ISO)? Or must use both?
I'm confused

I really look forward to hearing back from you.

Regards

Ibrahim Shalaby

Added (1). Of coarse I meant shutter speed not "stutter"
Sorry for the typing mistake

Shutter, not stutter. And EV is not exposure compensation, it means exposure value.

You can use one or the other, or both if you need to. Exposure compensation is used because of how the meter reacts to dark or light subjects.

As an example, if you were to take a picture of a white cat, the metering in the camera would likely try to make the cat gray; this is what it's designed to do If you want that white cat to remain white, you'd have to add two stops (overexpose). You do this by slowing the shutter speed two stops, increasing the aperture two stops or splitting the two of them one stop each.

I EV is one stop. The digital camera allows you 1/3 stop as well. EV is the unit of exposure compensation. And as the name suggests, you are trying to compensate the exposure that has been metered by the camera. What parameters you should alter (between ISO, shutter speed and aperture) would depend on the subject and the available lighting. If you don't wanrt to lose the depth of field you will alter the shutter speed, and so on…
The exposure compensation feature of the camera (the calculation is done automatically by the camera) is a help when you are in a hurry.
One drawback of this auto EV feature is that if the camera does not gets the required exposure by adjusting the aperture and shutter speed it would raise the ISO and would go on raising it till it gets the required exposure.

You can use either one (If you are on manual mode you don't really need to adjust the EV, you can do that by simply adjusting either the shutter speed or the aperture, or the iso. Doing this works the same as if you were adjusting the EV).

I use EV when I'm on one of the semi-automatic modes (like aperture-priority mode or shutter-priority mode, where the camera chooses the exposure for you). Changing the EV changes the exposure (since, for example, trying to change the aperture in aperture-priority mode will not change the exposure, the camera will keep the same exposure by automatically changing the shutter speed).

Really, you should read your camera manual, as I'm sure it explains all this in great detail. You would also be able to figure it out by fiddling with the settings and seeing the results.