A resistor is a fundamental electronic component that limits the flow of electric current in a circuit. It is used to control voltage and current levels, ensuring that other components operate safely and effectively. Resistors come in various types, including fixed, variable, and specialty resistors, each serving different purposes in electronic designs. In addition to their primary function of resistance, resistors can also help in dividing voltages and dissipating heat. They are essential in circuits found in everyday devices, from simple gadgets to complex machinery, making them a crucial element in the field of Electronics and Electrical Engineering.