What is the difference between algo trading and regular trading?

Algorithmic trading uses computer programs to generate and execute large market orders. Algorithmic trading's primary use is to control cost and risk. Use of Algorithmic trading began in the '90s. Regular trading includes tactics such as Arbitage, Market Making, Momentum Day Trading, Pattern Trading and Scalping. Pattern trading for example is trading that has the trader hold a trade for as little as one day up to a few weeks, then maximizing profits.