Digital multimeters (DMM) are electronic devices that help us measure electrical values and check the continuity in a circuit.- voltage and resistance input jack.The main parts of a digital multimeter are the display, the selection knob, the probes, and the input jacks.Selection knob: used to select the desired range of the quantity being measured.The most common quantities are DC voltage, DC current, AC voltage, AC current and resistance.Input jacks: These are the ports where you plug in the red and the black probes of the DMM.The red probe plugs into this jack when you measure voltage or resistance.The multimeter measures different electrical values.1.2.3.4.o V/?