A multimeter is an electronic testing device that combines several measurement functions into one unit. The simplest multimeters measure voltage, current and resistance. Advanced multimeters can also measure capacitance, conductance, frequency, inductance, temperature, continuity and more with application-specific attachments.
Digital multimeters typically feature a display, a dial to select different measurement functions, and test leads or a clamp to test components or wires. High-end multimeters also include a number of buttons that further specify the measurement characteristic or store and recall data.
Digital multimeters are preferred for their rugged construction, handheld use, and portability for fieldwork. Analog meters are less common, but applicable in situations where measurement values rapidly fluctuate.