The Relative Strength Index (RSI) is a technical indicator used in financial markets to assess the momentum and strength of price movements of an asset. RSI is calculated based on the ratio of the average gains to average losses over a specified period, typically 14 days. It provides a numerical value between 0 and 100, with values above 70 indicating overbought conditions, and values below 30 suggesting oversold conditions, helping traders identify potential trend reversals or price corrections.