Difference between conv and fftfilt in MATLAB

What is the difference between the 'conv' and 'fftfilt' functions in MATLAB?

I read that conv is done in time-domain, while fftfilt first does FFT using the overlap-add method before doing the multiplication in frequency-domain. However, I'm not sure how these different approaches will affect the results (as I thought that convolution in the time-doma开发者_运维百科in is the same as multiplication in the frequency domain), and when I should use one over the other?

---

The transformation from time-domain to frequency-domain has its own computational price. Although the result should be the same the timing can be different depending on input length. You can find the following post useful. For more in depth analysis you could read about FFT/Convolution in time and frequency domain.