Resistor

From Electronics Wiki

A resistor is a two-terminal electronic component that opposes an electric current by producing a voltage drop between its terminals in proportion to the current, that is, in accordance with Ohm's law: V = IR. The electrical resistance R is equal to the voltage drop V across the resistor divided by the current I through the resistor. Resistors are used as part of electrical networks and electronic circuits.

As with many electronic components, resistors can have fixed values or variable values. Typically when a resistor is referred to as a "resistor" then it is implicitly a fixed value resistor. Variable resistors are more often referenced by more specific names like potentiometers (or just pots), trimmer potentiometers (aka trimpots), or rheostats. While fixed resistors are nearly always internal components on electronic devices, variable resistors are often part of user interface features such as control knobs and sliders.