Algo trading, short for algorithmic trading, means letting a computer program place and manage orders based on rules you define in advance. The rules might be as simple as buy Nifty futures when the 20-day moving average crosses above the 50-day, or far more complex. Large institutions generate most of the algo volume on NSE and BSE. Retail traders in India can use broker APIs, but SEBI has been tightening the rules for retail algos, so check what your broker currently permits. An algo removes emotion and speed problems, but it does not remove risk. A badly tested rule can lose money faster than a person can, because it never hesitates. Beginners should understand manual trading, backtesting and position sizing first. Automation is a tool for a tested process, not a shortcut around learning one.