A resistor is an element that limits the flow of current. It can control the magnitude of current, and also be used to regulate voltage. When current flows through a resistor, heat is generated, so resistors can also be used as heating elements.

Why use resistors?

Resistors can limit the size of the current. This is crucial for protecting components from damage due to excessive current.

Resistance can control voltage. This is crucial for precisely regulating the working voltages of multiple different components within a system.

Resistors can heat up components. This is important for more efficiently converting energy into heat when using heating elements in a system.