Thin Film Resistors (SMD) are small, low-cost resistors that are used to reduce the amount of current that passes through a circuit. They are made using a thin film of either polymer or ceramic material which is then deposited onto a conductor. The thickness of this film can be varied to create different resistance levels. Thin film resistors require a very high level of precision during production and are typically used in applications such as signal processing, communication devices and instrumentation. They are often preferred over carbon-based or wire wound resistors due to their superior performance and reliability.