This video is about identifying capacitor polarity. Some capacitors are unpolarized like resistors, so it means they can be placed either way in a circuit. Other types, such as electrolytic capacitors, have to be placed in a particular direction in a circuit. And that's usually indicated by a plus sign at one end. Big capacitors, which means pretty much anything bigger than a microfarad, are usually electrolytic. Here's a small electrolytic capacitor, and you can see an indication on it of the minus sign indicating which pin is the negative pin. Here's a big electrolytic capacitor. Here's what it looks like from the top. Here's the label on the side. You see it's 11,000 microfarads, so that's big. If we put a nonpolarized capacitor in a circuit, it doesn't matter which way we connect it. And the symbol doesn't show you any polarization, so it's easy to see. A polarized capacitor has this curved bar on the bottom that indicates which way it's supposed to go in a circuit. So the curve contact goes to the lower voltage. If we put a polarized capacitor in the wrong way, then it can explode. Don't do this. So capacitors are labeled in different ways. So on a big capacitor, the label can go next to the pin. Here you see the plus sign around next to the positive pin. Here's another capacitor. Notice there's a positive sign here, so that means that the pin that's closest, which is this one, is the positive pin. Here's another capacitor, and we see a negative sign, so that means the closest pin to it, this one, is the negative pin. Here we have an axial capacitor, which means there's a lead coming out of each end. And again, we have a negative sign with an arrow that points to this lead, meaning that's the negative lead. Here's another capacitor. You see the positive signs here indicate that the pin closest to that, which is this pin here, is the positive pin. So that's how you identify the polarity of capacitors.