# Frequency of the wave in frequency domain

If we have a 1-dimensional wave in time domain, it can be represented in frequency domain with x axis indicating the frequency of the wave and y axis indicating amplitude/magnitude of the wave. But what about a 2-dimensional wave in case of images in Frequency Domain? Because in 2-dimensional wave we have a cordinate (x,y) to denote the magnitude. So what is the frequency in this case?