I assume you are talking about moving a microscope slide around on the stage of a microscope. If you are using a standard lab microscope, the lenses in the microscope flip the image over in the process of magnifying it, so that what you see in the eyepiece is actually upside down and backwards relative to what is really on the slide. (To see a diagram of why this is so, check out this link.) Because of this, when you move the slide around on the stage, the image moves in opposition - moving the slide to the left causes the image to appear to shift to the right, and the converse. This takes some getting used to when you are first learning how to work with a microscope.