Voltage regulators and surge protectors are two similar devices used to help maintain the correct voltage for electrical devices. However, each type of device works in a slightly different manner, and is used in slightly different situations.
Voltage regulators are deviced used to provide a constant voltage to any connected electrical devices. If the voltage given to an electrical device is too high or too low, it could cause damage. Voltage regulators help prevent this, adjusting the provided voltage up or down to keep it at the correct levels.
Surge protectors, also known as surge suppressors, are a device used to protect against electrical surges. Electrical surges can have many causes, such as lightning strikes or faulty wiring, and can severely damage electrical devices connected to the power grid. When a surge is detected, a surge protector diverts the surge to the ground, preventing it from reaching the connected devices.
Surge protectors are normally used with expensive electronic devices, such as computers or televisions. Since electric surges can happen almost anywhere under the right conditions, surge protectors are usually considered an easy and cheap investment.
Voltage regulators are not used as often as surge protectors, but can be useful in certain situations. Some households or business may receive so called "dirty power," where the power fluctuates frequently. Voltage regulators can be used in such situations to even out the power supply and help protect electrical devices.