Originally Posted by
TomsHardware.com
"Manufacturers generally use the term "dpi," which is inappropriate here because we're not talking about dots per inch. Instead, it's the number of measurements the mouse can register over a given distance that counts. The more measurements you take, the more precise the instantaneous positioning will be. But at the same time, the speed of the mouse increases. This has several repercussions in terms of use. First of all, you go to the spot you want to go to faster by moving the mouse less. The trade-off is that any movement, however infinitesimal, will be detected, which can actually work against preciseness. And to make things just a little more complicated, the resolution of the mouse also depends on the resolution of the monitor. If you increase screen resolution for a given mouse resolution, the movement will be longer."