Public futures markets were established in the 19th century[1] to allow transparent, standardized, and efficient hedging of agricultural commodity prices; they have since expanded to include futures contracts for hedging the values of energy, precious metals, foreign currency, and interest rate fluctuations.
Hedging is the practice of taking a position in one market to offset and balance against the risk adopted by assuming a position in a contrary or opposing market or investment. The word hedge is from Old English hecg, originally any fence, living or artificial. The use of the word as a verb in the sense of "dodge, evade" is first recorded in the 1590s; that of insure oneself against loss, as in a bet, is from the 1670s.[2]
The way a simple forex hedge protects you is that it allows you to trade the opposite direction of your initial trade without having to close that initial trade. It can be argued that it makes more sense to close the initial trade for a loss and place a new trade in a better spot. This is part of trader discretion. As a trader, you certainly could close your initial trade and enter the market at a better price.
The main reason that you want to use hedging on your trades is to limit risk. Hedging can be a bigger part of your trading plan if done carefully. It should only be used by experienced traders that understand market swings and timing. Playing with hedging without adequate trading experience could be a disaster for your account.
The advantage of using the hedge is that you can keep your trade on the market and make money with a second trade that makes profit as the market moves against your first position. When you suspect the market is going to reverse and go back in your initial trades favor, you can set a stop on the hedging trade, or just close it.