An analog oscilloscope is a device used to visualize electrical signals. It displays waveforms on a screen, allowing users to see how voltage changes over time. The device uses a cathode ray tube (CRT) to create images, where the horizontal axis represents time and the vertical axis represents voltage. These oscilloscopes are commonly used in electronics and engineering to troubleshoot circuits and analyze signal behavior. Unlike digital oscilloscopes, which convert signals into digital data, analog oscilloscopes provide a continuous representation of the waveform, making them useful for observing real-time changes in signals.