Resistors are one of the most common electronic devices found. They limit current in an electrical circuit and work equally well with both AC and DC currents. Resistors are typically characterized by two primary properties: resistance and wattage. Resistance refers to the amount of resistance to electrical current and is measured in Ohms. Wattage refers to the maximum amount of power loss in the form of heat the resistor can withstand without damage, and it measured in Watts. The size of a resistor is directly related to its Wattage rating. Sizes can range from tiny surface mount (SMT) flea-sized resistors to massive 1000 Watt power resistors.