Microscopy is a tool used by scientists to look at very small things that are too small for the eye to see. An acronym is a word made up of the first letter of each word in a phrase. For example, in microscopy, the acronym "TEM" stands for "transmission electron microscopy." This means that a microscope is used to shoot electrons (small particles) through a very thin sample to form an image. This allows scientists to see very small details of the sample.