High-frequency trading involves using computer algorithms to analyze market data and make trades within microseconds. It has grown significantly since the 2000s due to advances in technology that allow for extremely low latency trading. In 2010, the Tokyo Stock Exchange introduced a new system that reduced latency to 2 milliseconds, enabling high-frequency traders to dominate trading, executing over 1,000 orders per second and accounting for 72% of trades. While high-frequency trading provides benefits like increased liquidity and narrower spreads, it is also criticized for strategies like front-running that see order flows and trade based on that information.