Surge protector are used to protect your device from high voltage spike..in belkin they generally use a metal oxide variable resistor to bypass the excess voltage to ground..now it only bypasses the voltage not regulate it i.e line noise and other factors of line voltage.
Where a voltage stabilizer will give you a fixed output voltage regardless of input voltage by using various component such as reference voltage generator, wave form comparator, line filter, wave form shaper and add or subtracting circuit along with an auto transformer where various relays are selected on the basis of how much output voltage u want.
