What is Difference Between P mode and A mode in Nikon D3100

[Ysarex]

the camera will match the change you make with an equivlant exposure in the auto/semi-auto modes. this may or may not be your desired result when considering other aspects of the shot than exposure; DoF, motion control, etc.
so, as i understand it, Program, Shutter and Aperture modes will yield the same exposure value, but may have different yet equivalent exposures, basically giving the artistic control away to the camera.

You do not give artistic control to the camera by using P, S or A modes. In fact with the camera mentioned by the OP, unless you are using external flash or an external metering source, it's fair to argue that you gain maximum artistic control with the camera in Program mode. Maximum artistic control is afforded by maximum efficiency. The less you have to do to physically adjust the camera to reach your desired exposure parameters the more time and energy you have to devote to artistic control. P mode has the efficiency edge -- it may be slight but an edge is and edge.

Joe

 

[ph0enix]

OP: Please read pages 72-76 in your camera's manual. Here it is in PDF format in case a hard copy didn't come with the camera:
http://www.nikonusa.com/pdf/manuals/kie88335f7869dfuejdl=-cww2/D3100_EN.pdf