The Fast Fourier Transform (FFT) is a mathematical algorithm that quickly converts a signal from its original domain, often time or space, 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 fields like audio processing, image analysis, and communications. By breaking down complex signals into simpler components, the FFT allows for efficient computation, reducing the time needed to perform these calculations. This efficiency is crucial in applications such as digital signal processing and data compression, where speed and accuracy are essential for handling large amounts of information.