The Fourier transform is a mathematical technique that transforms a function of time (or space) into a function of frequency. It helps to analyze the different frequency components present in a signal, making it easier to understand complex waveforms. This transformation is widely used in various fields, including signal processing, image analysis, and quantum physics. By converting signals into the frequency domain, the Fourier transform allows for easier manipulation and filtering of data. It reveals how much of each frequency is present in the original signal, enabling applications like audio compression and spectral analysis.