Different electronic components are used for different things. When you need to limit the flow of current to a device a resistor would be the component used. But the type of resistor and what extent of a limit that is needed will influence what is used.

Given resistors oppose and can regulate the flow of an electrical charge going through a component, usually an electrical circuit. But if you wanted to stop the flow of electricity in just one direction a diode can and often is used. A “semiconductor component that allows most of the electric current or flows of electrons in one direction (forward direction) while blocks most of the electric current in opposite direction (reverse direction). It consists of two terminals or electrodes: cathode and anode. The p-type material of a diode acts as anode and the n-type material acts as cathode,” we are informed.

Resistors, actually, are used to limit the excess flow of current.  Voltage and electrons come into play. “Think of voltage as the pressure or force that is propelling the electrons” and “the number or amount of electrons passing a given point at any one time” is how the current is measured. “Resistors do just what their name says; they resist. You can use them to limit either current or voltage, depending upon whether they are wired in series (one after the other), or parallel (sharing the same connection points, side-by-side,” StackExchange explains. 

Looking at Ohm’s Law -(V=IR) - where V is voltage and I is current and R is resistance - the resistance is generated by the resistor and the equation tells us what degree of resistor is needed. The law denotes a fundamental relationship of electronic circuits - if the resistance is fixed when you increase the voltage the current goes up - but impacted by the power of the resistor.