An oscilloscope is an electronic device used to measure and display electrical signals over a range of voltage and time. It consists of a CRT (cathode ray tube) or LCD (liquid crystal display) display, an amplifier, a vertical deflection system, and a horizontal deflection system. The vertical deflection system allows an electrical signal to be displayed on a vertical line, while the horizontal deflection system allows the signal to be displayed on a horizontal line, making it easier to view. The amplifier is used to amplify the signal so that it can be seen easily on the display. The oscilloscope can be used to measure frequency, amplitude, and phase of a signal. It can also be used to detect a variety of voltage, current, and temperature levels. As it can measure multiple signals, an oscilloscope is often used as a troubleshooting tool to identify faults in electronic circuits.