This document discusses different types of digital cameras and their basic principles of operation. It describes several types of digital cameras including compact, DSLR-like, mirrorless, compact system camera, and camcorder. It also outlines different types of camera lenses such as wide-angle, standard, telephoto, macro, and fisheye lenses. Finally, it explains the basic principles of digital cameras including image sensors, focus, display, exposure settings, metering, and white balance.