The Short-Time Fourier Transform (STFT) is a mathematical technique used to analyze signals that change over time. It breaks a signal into smaller segments, applying the Fourier Transform to each segment to capture both time and frequency information. This allows for the examination of how the frequency content of a signal evolves, making it useful in various applications like audio processing and speech analysis. STFT is particularly effective for non-stationary signals, where frequency components vary with time. By using a sliding window approach, it provides a time-frequency representation, often visualized as a spectrogram. This representation helps in understanding complex signals in fields such as music, telecommunications, and medical imaging.