The frequency interval between neighbor DFT points is 1∕T, where T is the time-window in which the signal is sampled. This frequency interval is called frequency resolution, which is determined only by the length of the time-window and is independent of the sampling frequency. If the time-window is fixed, increasing the sampling frequency only increase the bandwidth (the frequency range of DFT) and the frequency interval between neighbor DFT points are still 1∕T, i.e., the frequency resolution is not changed. In summary, bandwidth is the highest frequency that is captured in the Fourier transform, equal to half the sampling rate. Frequency Resolution is 1∕T, which is the spacing between samples in the frequency domain.