What is the function of a voltage regulator?

Gechy Electric Co.,Ltd tell you the voltage regulator function, answer as below shows,

Electric components are built to receive a specified amount of volts and can be seriously damaged. 

If the power surges, and low voltages may not be able to power up a component to its full functionality. 

Regulators ensure the voltage is within a range the electric components can safely receive and use to optimally function. 

Depending on its design, a regulator can regulate single or multiple DC or AC voltages.