This document provides an overview of an oscilloscope. It begins with an introduction that defines an oscilloscope and describes what it can be used for. It then explains how an oscilloscope works through a block diagram of its major components, including the cathode ray tube, vertical and horizontal amplifiers, delay line, time base circuit, and trigger circuit. Each of these components is then described in more detail. The document also notes the different types of oscilloscopes and provides some examples of common uses.