Re: what is the difference in resolution, DPI, and Megapixels in relation to a

Your full question isn't coming through, but I will give you a brief 
summary.  Resolution is how small an object you can see when you are 
trying to differentiate items in a picture.  Think about looking at a 
ruler.  If you can make out where the inch markings are and they aren't 
blurry, the that's your resolution.  Now, that seems kinda silly, but 
imagine if your ruler was marked down tot he 1/64th of an inch.  Do you 
think you could distinguish between those marks?  How about 1/32nd?

The resolution will depend on a lot of things, but mainly the number of 
megapixels you have.  Each megapixel contains different information 
(colorwise) and the more you have, the better your picture is going to 
be.  This is entangled with the color scheme of the camera, if each 
megapixel only reads black or white, then you will have less resolution 
than if it registers 8 shades of gray, or 64, and so on.  And then add 
color tot he mix and you have a whole lot more options.

DPI, or dots per inch, refers to the fineness your printer will be able 
to show when you are trying to print the picture out.

A pretty descent website you can check out:
 http://www.digicamguides.com/

It will walk you through if you are in the buying mode.