What is a multimeter?

A multimeter measures volts, ohms and usually current. In appliance work most of its use is dead testing. Power off, checking continuity and resistance through elements, fuses, switches and sensors. A model with min/max capture is worth having because it catches intermittent faults that appear only mid cycle. Learning to walk the power path with a meter, rather than swapping parts hopefully, is the difference between repairing appliances and gambling on them.