A multimeter is a handy tool that you use to measure electricity, just like you would use a ruler to measure distance, a stopwatch to measure time, or a scale to measure weight. The neat thing about a multimeter is that, unlike a ruler, watch, or scale, it can measure different things — kind of like a multi-tool. Most multimeters have a knob on the front that lets you select what you want to measure. Below is a picture of a typical multimeter. There are many different multimeter models; visit the multimeter gallery for labeled pictures of additional models.