Resistors can be fabricated in a variety of ways. The most common type in electronic devices and systems is the carbon-composition resistor. Fine granulated carbon (graphite) is mixed with clay and hardened. The resistance depends on the proportion of carbon to clay; the higher this ratio, the lower the resistance.
Another type of resistor is made from winding Nichrome or similar wire on an insulating form. This component, called a wire-wound resistor, is able to handle higher currents than a carbon-composition resistor of the same physical size. However, because the wire is wound into a coil, the component acts as an inductor as well as exhibiting resistance. This does not affect performance in DC circuits but can have an adverse effect in AC circuits because inductance renders the device sensitive to changes in frequency.