The Fast Fourier Transform (FFT) is a mathematical algorithm that quickly converts a signal from its original time domain into the frequency domain. This transformation helps us understand the different frequencies present in a signal, making it easier to analyze and process data in various fields like audio processing, image analysis, and communications. By breaking down complex signals into simpler components, the FFT allows for efficient data compression and noise reduction. It is widely used in applications such as music synthesis, medical imaging, and digital signal processing, enabling faster computations and improved performance in technology and research.