Algorithmic trading and high-frequency trading (HFT) are related but distinct approaches to trading in financial markets. Both involve the use of computer algorithms to facilitate the execution of trades, but there are some key differences between the two approaches.

Algorithmic trading refers to the use of computer algorithms to design and execute trades based on predefined rules and parameters. Algorithmic trading can be used by traders to implement a wide variety of trading strategies, including high-frequency trading, but it is not limited to high-frequency trading specifically. Algorithmic trading is typically used to automate the process of executing trades and can be used to trade a variety of financial instruments, including stocks, futures, and currencies.

High-frequency trading, on the other hand, refers to a specific type of algorithmic trading that is characterized by the use of advanced technology and high-speed computer systems to execute a large number of trades in a very short period of time. High-frequency traders often use complex algorithms and sophisticated technology to analyze market conditions and make rapid trading decisions, and they may hold positions for only a very short time before closing them out.

Overall, algorithmic trading and high-frequency trading are both ways of using computer algorithms to facilitate the execution of trades, but high-frequency trading is a specific type of algorithmic trading that is characterized by the use of advanced technology and high-speed systems to execute a large number of trades in a very short period of time.