The role of a resistor in an electronic circuit is to control or limit the flow of electric current. It acts as a passive component that offers resistance to the flow of electrons. By providing a specific resistance value, resistors regulate the amount of current that can pass through them. This resistance is measured in ohms (Ω). Resistor values can be chosen to achieve specific voltage levels, current levels, or to ensure components of a circuit receive the appropriate amount of power. Furthermore, resistors can help divide voltages, reduce signal amplitude, set biasing levels, and protect components from excessive current flow. Overall, resistors play a fundamental role in controlling and manipulating the behavior of electric current in electronic circuits.