High frequency trading (or HFT) is a form of advanced trading platform that processes a high numbers of trades very quickly using powerful computing technology. It can be used to either find the best price for a single large order, or to find opportunities for profit in the market in real time.
The algorithms behind high frequency trading tend to be extremely complex, allowing the program to trade across several markets at once as conditions are met. The advantage of HFT is largely down to how quickly the platform can process trades, so the focus is on the power of computers used and location of computing programs. By placing themselves nearby to the exchanges taking orders, HFT firms can gain millisecond advantages over their rivals.