A multimeter is a device that measures multiple electrical properties. It can measure things like voltage, current, and resistance. A voltmeter is a type of multimeter that specializes in measuring voltage. A voltmeter can measure direct current (DC) and alternating current (AC) voltages. Both multimeters and voltmeters are used in the fields of electronics and electrical maintenance. They are often used to troubleshoot and diagnose problems with circuits. They are also used to measure voltage values in different stages of a circuit and to determine whether there is sufficient power supply for a device to work properly.