Confocal Microscopy uses a microscope in which a certain area of a sample, a point source and a small aperture are in conjugate planes, as shown in the diagram below. This means that only a small area is illuminated at any one time. This reduces the damage caused to cells by photobleaching and gives clearer pictures than standard fluorescence microscopy as the amount of out of focus light collected is greatly reduced.
The ARCHA confocal Mircroscope system is the SP5 TCS II MP made by Leica Microsystems. The list of its key features and their applications is extensive and detailed, so some are linked to their own pages.