The oscillator indicator is a popular tool in forex trading used to identify potential market reversals and overbought or oversold conditions. It measures the momentum and strength of price movements, helping traders determine when a market may be reaching extremes. Oscillators, such as the Relative Strength Index (RSI) or Stochastic Oscillator, provide signals through various levels or crossovers, indicating potential buy or sell opportunities. By understanding how to interpret and use oscillator indicators effectively, traders can enhance their analysis and make informed trading decisions based on price momentum and market conditions.