A Fourier transform function (in frequency) can be converted back into a function in time by another integral operator called inverse Fourier transform. It is customarily said that it transforms the frequency domain into the time domain. The Fourier transform has many applications in physics and engineering. Fourier transformation the time domain to the frequency domain converts differential equations into algebraic equations and convolution into multiplication. This often results in simplification of needed mathematical manipulations.-A Fourier transform function (in frequency) can be converted back into a function in time by another integral operator called inverse Fourier transform. It is customarily said that it transforms the frequency domain into the time domain. The Fourier transform has many applications in physics and engineering. Fourier transformation　the time domain to the frequency domain converts differential equations into algebraic equations and convolution into multiplication. This often results in simplification of needed mathematical manipulations.