Various forms of microscopy are widely used in biomedical research as well as in clinical medicine. Major classes of microscopy include: a) optical microscopy (wide-field, fluorescence, laser-scanning confocal, Raman, bioluminescence, near-field/scanning-probe, super-resolution, non-linear, light-sheet, intravital), together with a variety of fluorescent and other probes (dyes, fluorescent proteins, small-molecules); and b) electron microscopy, in both transmission and surface-scanning modes. The goal of this module is to introduce the basic physical principles of the different forms of microscopy and survey the different techniques, instruments, and probes used in studying bio-specimens (cells, tissues, biomaterials), illustrating these with examples of biomedical applications. The role of digital techniques and image processing/analysis will be considered.