Overlap is the amount of time data used within a time signal by two neighboring Fast Fourier Transforms (FFT). Overlap is expressed in percentage. While windowing a signal ensures that there is no spectral leakage, some amount of information is lost due to the windowing process. Overlapping is one way to overcome the limitations of windowing. Learn about the process of overlapping a time signal in this video. Other relevant videos: Windowing explained: Types of windowing explained: